Update dependency SharpCompress to 0.50.0

Translation: Jellyfin/Jellyfin
Translate-URL: https://translate.jellyfin.org/projects/jellyfin/jellyfin-core/he/

.github/workflows/ci-codeql-analysis.yml

@@ -24,21 +24,21 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
 
     - name: Setup .NET
-      uses: actions/setup-dotnet@9a946fdbd5fb07b82b2f5a4466058b876ab72bb2 # v5.3.0
+      uses: actions/setup-dotnet@26b0ec14cb23fa6904739307f278c14f94c95bf1 # v5.4.0
       with:
         dotnet-version: '10.0.x'
 
     - name: Initialize CodeQL
-      uses: github/codeql-action/init@8aad20d150bbac5944a9f9d289da16a4b0d87c1e # v4.36.2
+      uses: github/codeql-action/init@99df26d4f13ea111d4ec1a7dddef6063f76b97e9 # v4.37.0
       with:
         languages: ${{ matrix.language }}
         queries: +security-extended
 
     - name: Autobuild
-      uses: github/codeql-action/autobuild@8aad20d150bbac5944a9f9d289da16a4b0d87c1e # v4.36.2
+      uses: github/codeql-action/autobuild@99df26d4f13ea111d4ec1a7dddef6063f76b97e9 # v4.37.0
 
     - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@8aad20d150bbac5944a9f9d289da16a4b0d87c1e # v4.36.2
+      uses: github/codeql-action/analyze@99df26d4f13ea111d4ec1a7dddef6063f76b97e9 # v4.37.0

.github/workflows/ci-compat.yml

@@ -11,13 +11,13 @@ jobs:
     permissions: read-all
     steps:
       - name: Checkout repository
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
         with:
           ref: ${{ github.event.pull_request.head.sha }}
           repository: ${{ github.event.pull_request.head.repo.full_name }}
 
       - name: Setup .NET
-        uses: actions/setup-dotnet@9a946fdbd5fb07b82b2f5a4466058b876ab72bb2 # v5.3.0
+        uses: actions/setup-dotnet@26b0ec14cb23fa6904739307f278c14f94c95bf1 # v5.4.0
         with:
           dotnet-version: '10.0.x'
 
@@ -40,14 +40,14 @@ jobs:
     permissions: read-all
     steps:
       - name: Checkout repository
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
         with:
           ref: ${{ github.event.pull_request.head.sha }}
           repository: ${{ github.event.pull_request.head.repo.full_name }}
           fetch-depth: 0
 
       - name: Setup .NET
-        uses: actions/setup-dotnet@9a946fdbd5fb07b82b2f5a4466058b876ab72bb2 # v5.3.0
+        uses: actions/setup-dotnet@26b0ec14cb23fa6904739307f278c14f94c95bf1 # v5.4.0
         with:
           dotnet-version: '10.0.x'
 

.github/workflows/ci-format.yml

@@ -15,9 +15,9 @@ jobs:
   format-check:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
 
-      - uses: actions/setup-dotnet@9a946fdbd5fb07b82b2f5a4466058b876ab72bb2 # v5.3.0
+      - uses: actions/setup-dotnet@26b0ec14cb23fa6904739307f278c14f94c95bf1 # v5.4.0
         with:
           dotnet-version: ${{ env.SDK_VERSION }}
 

.github/workflows/ci-tests.yml

@@ -20,9 +20,9 @@ jobs:
 
     runs-on: "${{ matrix.os }}"
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
 
-      - uses: actions/setup-dotnet@9a946fdbd5fb07b82b2f5a4466058b876ab72bb2 # v5.3.0
+      - uses: actions/setup-dotnet@26b0ec14cb23fa6904739307f278c14f94c95bf1 # v5.4.0
         with:
           dotnet-version: ${{ env.SDK_VERSION }}
 

.github/workflows/commands.yml

@@ -24,7 +24,7 @@ jobs:
           reactions: '+1'
 
       - name: Checkout the latest code
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
         with:
           token: ${{ secrets.JF_BOT_TOKEN }}
           fetch-depth: 0
@@ -40,12 +40,12 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: pull in script
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
         with:
           repository: jellyfin/jellyfin-triage-script
 
       - name: install python
-        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
+        uses: actions/setup-python@ece7cb06caefa5fff74198d8649806c4678c61a1 # v6.3.0
         with:
           python-version: '3.14'
           cache: 'pip'

.github/workflows/issue-stale.yml

@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     if: ${{ contains(github.repository, 'jellyfin/') }}
     steps:
-      - uses: actions/stale@eb5cf3af3ac0a1aa4c9c45633dd1ae542a27a899 # v10.3.0
+      - uses: actions/stale@1e223db275d687790206a7acac4d1a11bd6fe629 # v10.4.0
         with:
           repo-token: ${{ secrets.JF_BOT_TOKEN }}
           ascending: true

.github/workflows/issue-template-check.yml

@@ -10,12 +10,12 @@ jobs:
       issues: write
     steps:
       - name: pull in script
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
         with:
           repository: jellyfin/jellyfin-triage-script
 
       - name: install python
-        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
+        uses: actions/setup-python@ece7cb06caefa5fff74198d8649806c4678c61a1 # v6.3.0
         with:
           python-version: '3.14'
           cache: 'pip'

.github/workflows/openapi-generate.yml

@@ -22,13 +22,13 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout Repository
-      uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
       with:
         ref: ${{ inputs.ref }}
         repository: ${{ inputs.repository }}
 
     - name: Configure .NET
-      uses: actions/setup-dotnet@9a946fdbd5fb07b82b2f5a4466058b876ab72bb2 # v5.3.0
+      uses: actions/setup-dotnet@26b0ec14cb23fa6904739307f278c14f94c95bf1 # v5.4.0
       with:
         dotnet-version: '10.0.x'
 

.github/workflows/openapi-pull-request.yml

@@ -10,7 +10,7 @@ jobs:
       base_ref: ${{ steps.ancestor.outputs.base_ref }}
     steps:
     - name: Checkout Repository
-      uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
       with:
         ref: ${{ github.event.pull_request.head.sha }}
         repository: ${{ github.event.pull_request.head.repo.full_name }}

.github/workflows/pull-request-stale.yaml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     if: ${{ contains(github.repository, 'jellyfin/') }}
     steps:
-      - uses: actions/stale@eb5cf3af3ac0a1aa4c9c45633dd1ae542a27a899 # v10.3.0
+      - uses: actions/stale@1e223db275d687790206a7acac4d1a11bd6fe629 # v10.4.0
         with:
           repo-token: ${{ secrets.JF_BOT_TOKEN }}
           ascending: true

.github/workflows/release-bump-version.yaml

@@ -33,7 +33,7 @@ jobs:
           yq-version: v4.9.8
 
       - name: Checkout Repository
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
         with:
           ref: ${{ env.TAG_BRANCH }}
 
@@ -66,7 +66,7 @@ jobs:
       NEXT_VERSION: ${{ github.event.inputs.NEXT_VERSION }}
     steps:
       - name: Checkout Repository
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
         with:
           ref: ${{ env.TAG_BRANCH }}
 

Directory.Packages.props

@@ -28,10 +28,10 @@
     <PackageVersion Include="MetaBrainz.MusicBrainz" Version="8.0.1" />
     <PackageVersion Include="Microsoft.AspNetCore.Authorization" Version="10.0.9" />
     <PackageVersion Include="Microsoft.AspNetCore.Mvc.Testing" Version="10.0.9" />
-    <PackageVersion Include="Microsoft.CodeAnalysis.BannedApiAnalyzers" Version="4.14.0" />
-    <PackageVersion Include="Microsoft.CodeAnalysis.Common" Version="5.3.0" />
-    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="5.3.0" />
-    <PackageVersion Include="Microsoft.CodeAnalysis.Analyzers" Version="5.3.0" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.BannedApiAnalyzers" Version="5.6.0" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.Common" Version="5.6.0" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="5.6.0" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.Analyzers" Version="5.6.0" />
     <PackageVersion Include="Microsoft.Data.Sqlite" Version="10.0.9" />
     <PackageVersion Include="Microsoft.EntityFrameworkCore.Design" Version="10.0.9" />
     <PackageVersion Include="Microsoft.EntityFrameworkCore.Relational" Version="10.0.9" />
@@ -47,7 +47,7 @@
     <PackageVersion Include="Microsoft.Extensions.Http" Version="10.0.9" />
     <PackageVersion Include="Microsoft.Extensions.Logging" Version="10.0.9" />
     <PackageVersion Include="Microsoft.Extensions.Options" Version="10.0.9" />
-    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.6.0" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.7.0" />
     <PackageVersion Include="MimeTypes" Version="2.5.2" />
     <PackageVersion Include="Morestachio" Version="5.0.1.670" />
     <PackageVersion Include="Moq" Version="4.18.4" />
@@ -67,7 +67,7 @@
     <PackageVersion Include="Serilog.Sinks.File" Version="7.0.0" />
     <PackageVersion Include="Serilog.Sinks.Graylog" Version="3.1.1" />
     <PackageVersion Include="SerilogAnalyzer" Version="0.15.0" />
-    <PackageVersion Include="SharpCompress" Version="0.49.1" />
+    <PackageVersion Include="SharpCompress" Version="0.50.0" />
     <PackageVersion Include="SharpFuzz" Version="2.3.0" />
     <PackageVersion Include="SkiaSharp" Version="3.119.4" />
     <PackageVersion Include="SkiaSharp.HarfBuzz" Version="3.119.4" />
@@ -75,8 +75,8 @@
     <PackageVersion Include="SmartAnalyzers.MultithreadingAnalyzer" Version="1.1.31" />
     <PackageVersion Include="StyleCop.Analyzers" Version="1.2.0-beta.556" />
     <PackageVersion Include="Svg.Skia" Version="3.7.0" />
-    <PackageVersion Include="Swashbuckle.AspNetCore.ReDoc" Version="10.2.1" />
-    <PackageVersion Include="Swashbuckle.AspNetCore" Version="10.2.1" />
+    <PackageVersion Include="Swashbuckle.AspNetCore.ReDoc" Version="10.2.3" />
+    <PackageVersion Include="Swashbuckle.AspNetCore" Version="10.2.3" />
     <PackageVersion Include="System.Text.Json" Version="10.0.9" />
     <PackageVersion Include="TagLibSharp" Version="2.3.0" />
     <PackageVersion Include="z440.atl.core" Version="7.15.3" />

Emby.Naming/TV/EpisodePathParser.cs

@@ -125,7 +125,7 @@ namespace Emby.Naming.TV
                             result.Success = true;
                         }
                     }
-                    else if (DateTime.TryParse(match.Groups[0].ValueSpan, out date))
+                    else if (DateTime.TryParse(match.Groups[0].ValueSpan, CultureInfo.InvariantCulture, out date))
                     {
                         result.Year = date.Year;
                         result.Month = date.Month;

Emby.Server.Implementations/ApplicationHost.cs

@@ -93,6 +93,9 @@ using MediaBrowser.Model.Net;
 using MediaBrowser.Model.Serialization;
 using MediaBrowser.Model.System;
 using MediaBrowser.Model.Tasks;
+using MediaBrowser.Providers.Books;
+using MediaBrowser.Providers.Books.ComicBookInfo;
+using MediaBrowser.Providers.Books.ComicInfo;
 using MediaBrowser.Providers.Lyric;
 using MediaBrowser.Providers.Manager;
 using MediaBrowser.Providers.Plugins.ListenBrainz;
@@ -496,6 +499,14 @@ namespace Emby.Server.Implementations
             serviceCollection.AddSingleton<ListenBrainzLabsClient>();
             serviceCollection.AddSingleton<ListenBrainzSimilarArtistProvider>();
 
+            // register the generic local metadata provider for comic files
+            serviceCollection.AddSingleton<ComicProvider>();
+
+            // register the actual implementations of the local metadata provider for comic files
+            serviceCollection.AddSingleton<IComicProvider, ComicBookInfoProvider>();
+            serviceCollection.AddSingleton<IComicProvider, ExternalComicInfoProvider>();
+            serviceCollection.AddSingleton<IComicProvider, InternalComicInfoProvider>();
+
             serviceCollection.AddSingleton(NetManager);
 
             serviceCollection.AddSingleton<ITaskManager, TaskManager>();

Emby.Server.Implementations/Dto/DtoService.cs

@@ -71,6 +71,8 @@ namespace Emby.Server.Implementations.Dto
             {
                 BaseItemKind.Person, [
                     BaseItemKind.Audio,
+                    BaseItemKind.AudioBook,
+                    BaseItemKind.Book,
                     BaseItemKind.Episode,
                     BaseItemKind.Movie,
                     BaseItemKind.LiveTvProgram,
@@ -167,9 +169,13 @@ namespace Emby.Server.Implementations.Dto
 
             // Batch-fetch user data for all items
             Dictionary<Guid, UserItemData>? userDataBatch = null;
+            IReadOnlyDictionary<Guid, VersionResumeData>? resumeDataBatch = null;
             if (user is not null && options.EnableUserData)
             {
                 userDataBatch = _userDataRepository.GetUserDataBatch(accessibleItems, user);
+
+                // For items with alternate versions, the most recently played version drives resume.
+                resumeDataBatch = _userDataRepository.GetResumeUserDataBatch(accessibleItems, user);
             }
 
             // Pre-compute collection folders once to avoid N+1 queries in CanDelete
@@ -248,7 +254,8 @@ namespace Emby.Server.Implementations.Dto
                     allCollectionFolders,
                     childCountBatch,
                     playedCountBatch,
-                    artistsBatch);
+                    artistsBatch,
+                    resumeDataBatch?.GetValueOrDefault(item.Id));
 
                 if (item is LiveTvChannel tvChannel)
                 {
@@ -309,7 +316,8 @@ namespace Emby.Server.Implementations.Dto
             List<Folder>? allCollectionFolders = null,
             Dictionary<Guid, int>? childCountBatch = null,
             Dictionary<Guid, (int Played, int Total)>? playedCountBatch = null,
-            IReadOnlyDictionary<string, MusicArtist[]>? artistsBatch = null)
+            IReadOnlyDictionary<string, MusicArtist[]>? artistsBatch = null,
+            VersionResumeData? resumeData = null)
         {
             var dto = new BaseItemDto
             {
@@ -353,7 +361,8 @@ namespace Emby.Server.Implementations.Dto
                     options,
                     userData,
                     childCountBatch,
-                    playedCountBatch);
+                    playedCountBatch,
+                    resumeData);
             }
 
             if (item is IHasMediaSources
@@ -369,7 +378,7 @@ namespace Emby.Server.Implementations.Dto
                 AttachStudios(dto, item);
             }
 
-            AttachBasicFields(dto, item, owner, options, artistsBatch);
+            AttachBasicFields(dto, item, owner, options, artistsBatch, user);
 
             if (options.ContainsField(ItemFields.CanDelete))
             {
@@ -538,7 +547,8 @@ namespace Emby.Server.Implementations.Dto
             DtoOptions options,
             UserItemData? userData = null,
             Dictionary<Guid, int>? childCountBatch = null,
-            Dictionary<Guid, (int Played, int Total)>? playedCountBatch = null)
+            Dictionary<Guid, (int Played, int Total)>? playedCountBatch = null,
+            VersionResumeData? resumeData = null)
         {
             if (item.IsFolder)
             {
@@ -600,6 +610,9 @@ namespace Emby.Server.Implementations.Dto
                         // Use pre-fetched user data
                         dto.UserData = GetUserItemDataDto(userData, item.Id);
                         item.FillUserDataDtoValues(dto.UserData, userData, dto, user, options);
+
+                        // For items with alternate versions, the most recently played version drives resume.
+                        resumeData?.ApplyTo(dto.UserData);
                     }
                     else
                     {
@@ -943,7 +956,8 @@ namespace Emby.Server.Implementations.Dto
         /// <param name="owner">The owner.</param>
         /// <param name="options">The options.</param>
         /// <param name="artistsBatch">Optional pre-fetched artist lookup shared across a batch of items.</param>
-        private void AttachBasicFields(BaseItemDto dto, BaseItem item, BaseItem? owner, DtoOptions options, IReadOnlyDictionary<string, MusicArtist[]>? artistsBatch = null)
+        /// <param name="user">The user, for per-user values such as the accessible media source count.</param>
+        private void AttachBasicFields(BaseItemDto dto, BaseItem item, BaseItem? owner, DtoOptions options, IReadOnlyDictionary<string, MusicArtist[]>? artistsBatch = null, User? user = null)
         {
             if (options.ContainsField(ItemFields.DateCreated))
             {
@@ -1257,7 +1271,12 @@ namespace Emby.Server.Implementations.Dto
 
                 if (options.ContainsField(ItemFields.MediaSourceCount))
                 {
-                    var mediaSourceCount = video.MediaSourceCount;
+                    // Match the per-user filtering of the media sources: versions the user cannot
+                    // access are not selectable, so they must not count towards the badge either.
+                    var mediaSourceCount = user is null
+                        || (!video.PrimaryVersionId.HasValue && video.LinkedAlternateVersions.Length == 0 && !video.HasLocalAlternateVersions)
+                            ? video.MediaSourceCount
+                            : video.GetAllVersions().Count(v => v.Id.Equals(video.Id) || v.IsVisibleStandalone(user));
                     if (mediaSourceCount != 1)
                     {
                         dto.MediaSourceCount = mediaSourceCount;

Emby.Server.Implementations/HttpServer/WebSocketConnection.cs

@@ -127,8 +127,12 @@ namespace Emby.Server.Implementations.HttpServer
                 {
                     receiveResult = await _socket.ReceiveAsync(memory, cancellationToken).ConfigureAwait(false);
                 }
-                catch (WebSocketException ex)
+                catch (Exception ex) when (ex is WebSocketException or ObjectDisposedException or OperationCanceledException)
                 {
+                    // ObjectDisposedException/OperationCanceledException: the socket was torn
+                    // down underneath us (e.g. by the keep-alive watchdog after the connection
+                    // was declared lost). Fall through so Closed is still raised and the
+                    // session can release this connection.
                     _logger.LogWarning("WS {IP} error receiving data: {Message}", RemoteEndPoint, ex.Message);
                     break;
                 }

Emby.Server.Implementations/IO/ManagedFileSystem.cs

@@ -691,7 +691,7 @@ namespace Emby.Server.Implementations.IO
             }
             catch (Exception ex) when (ex is UnauthorizedAccessException or DirectoryNotFoundException or SecurityException)
             {
-                _logger.LogError(ex, "Failed to enumerate path {Path}", path);
+                _logger.LogWarning("Failed to enumerate path \"{Path}\": {Message}", path, ex.Message);
                 return Enumerable.Empty<string>();
             }
         }

Emby.Server.Implementations/Images/CollectionFolderImageProvider.cs

@@ -5,6 +5,7 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
+using Jellyfin.Api.Extensions;
 using Jellyfin.Data.Enums;
 using Jellyfin.Database.Implementations.Enums;
 using MediaBrowser.Common.Configuration;
@@ -14,7 +15,6 @@ using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Providers;
 using MediaBrowser.Model.Entities;
 using MediaBrowser.Model.IO;
-using MediaBrowser.Model.Querying;
 
 namespace Emby.Server.Implementations.Images
 {
@@ -28,38 +28,7 @@ namespace Emby.Server.Implementations.Images
         {
             var view = (CollectionFolder)item;
             var viewType = view.CollectionType;
-
-            BaseItemKind[] includeItemTypes;
-
-            switch (viewType)
-            {
-                case CollectionType.movies:
-                    includeItemTypes = new[] { BaseItemKind.Movie };
-                    break;
-                case CollectionType.tvshows:
-                    includeItemTypes = new[] { BaseItemKind.Series };
-                    break;
-                case CollectionType.music:
-                    includeItemTypes = new[] { BaseItemKind.MusicArtist };  // Music albums usually don't have dedicated backdrops, so use artist instead
-                    break;
-                case CollectionType.musicvideos:
-                    includeItemTypes = new[] { BaseItemKind.MusicVideo };
-                    break;
-                case CollectionType.books:
-                    includeItemTypes = new[] { BaseItemKind.Book, BaseItemKind.AudioBook };
-                    break;
-                case CollectionType.boxsets:
-                    includeItemTypes = new[] { BaseItemKind.BoxSet };
-                    break;
-                case CollectionType.homevideos:
-                case CollectionType.photos:
-                    includeItemTypes = new[] { BaseItemKind.Video, BaseItemKind.Photo };
-                    break;
-                default:
-                    includeItemTypes = new[] { BaseItemKind.Video, BaseItemKind.Audio, BaseItemKind.Photo, BaseItemKind.Movie, BaseItemKind.Series };
-                    break;
-            }
-
+            var includeItemTypes = DtoExtensions.GetBaseItemKindsForCollectionType(viewType);
             var recursive = viewType != CollectionType.playlists;
 
             return view.GetItemList(new InternalItemsQuery
@@ -67,12 +36,9 @@ namespace Emby.Server.Implementations.Images
                 CollapseBoxSetItems = false,
                 Recursive = recursive,
                 DtoOptions = new DtoOptions(false),
-                ImageTypes = new[] { ImageType.Primary },
+                ImageTypes = [ImageType.Primary],
                 Limit = 8,
-                OrderBy = new[]
-                {
-                    (ItemSortBy.Random, SortOrder.Ascending)
-                },
+                OrderBy = [(ItemSortBy.Random, SortOrder.Ascending)],
                 IncludeItemTypes = includeItemTypes
             });
         }

Emby.Server.Implementations/Library/MediaSourceManager.cs

@@ -229,7 +229,11 @@ namespace Emby.Server.Implementations.Library
                 list.Add(source);
             }
 
-            return SortMediaSources(list, item.Id).ToArray();
+            var preferredId = mediaSources.Count > 0 && Guid.TryParse(mediaSources[0].Id, out var topSourceId)
+                ? topSourceId
+                : item.Id;
+
+            return SortMediaSources(list, preferredId).ToArray();
         }
 
         /// <inheritdoc />>
@@ -406,6 +410,69 @@ namespace Emby.Server.Implementations.Library
                         source.SupportsDirectStream = user.HasPermission(PermissionKind.EnablePlaybackRemuxing);
                     }
                 }
+
+                sources = SetAlternateVersionResumeStates(item, sources, user);
+            }
+
+            return sources;
+        }
+
+        /// <summary>
+        /// Populates each source's own playback position for the user and, when the queried item is a
+        /// primary, moves the most recently played version to the front so that resuming without an
+        /// explicit source selection plays the version that was last watched. A directly queried
+        /// alternate version keeps its own source first.
+        /// </summary>
+        /// <param name="item">The queried item.</param>
+        /// <param name="sources">The item's media sources.</param>
+        /// <param name="user">The user.</param>
+        /// <returns>The media sources, reordered when a version drives resume.</returns>
+        private IReadOnlyList<MediaSourceInfo> SetAlternateVersionResumeStates(BaseItem item, IReadOnlyList<MediaSourceInfo> sources, User user)
+        {
+            // For a video, multiple sources means alternate versions.
+            if (item is not Video video || sources.Count < 2)
+            {
+                return sources;
+            }
+
+            var versions = video.GetAllVersions();
+            if (versions.Count < 2)
+            {
+                return sources;
+            }
+
+            var userDataByVersion = _userDataManager.GetUserDataBatch(versions, user);
+            var dataBySourceId = new Dictionary<string, UserItemData>(versions.Count, StringComparer.OrdinalIgnoreCase);
+            foreach (var version in versions)
+            {
+                if (userDataByVersion.TryGetValue(version.Id, out var data))
+                {
+                    dataBySourceId[version.Id.ToString("N", CultureInfo.InvariantCulture)] = data;
+                }
+            }
+
+            foreach (var source in sources)
+            {
+                if (source.Id is not null
+                    && dataBySourceId.TryGetValue(source.Id, out var data)
+                    && data.PlaybackPositionTicks > 0)
+                {
+                    source.PlaybackPositionTicks = data.PlaybackPositionTicks;
+                }
+            }
+
+            // Reorder only for a resumable (in-progress) version;
+            // a completed version has no position to resume, so it must not be pulled to the front here.
+            var resumeSource = VersionPlaybackSelector.SelectMostRecentlyPlayed(
+                sources,
+                source => source.Id is not null ? dataBySourceId.GetValueOrDefault(source.Id) : null,
+                data => data.PlaybackPositionTicks > 0);
+
+            if (resumeSource is not null && !video.PrimaryVersionId.HasValue && !ReferenceEquals(sources[0], resumeSource))
+            {
+                var reordered = new List<MediaSourceInfo>(sources.Count) { resumeSource };
+                reordered.AddRange(sources.Where(s => !ReferenceEquals(s, resumeSource)));
+                return reordered;
             }
 
             return sources;

Emby.Server.Implementations/Library/Resolvers/PlaylistResolver.cs

@@ -1,6 +1,7 @@
 #nullable disable
 
 using System;
+using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using Jellyfin.Data.Enums;
@@ -46,7 +47,16 @@ namespace Emby.Server.Implementations.Library.Resolvers
                 }
 
                 // It's a directory-based playlist if the directory contains a playlist file
-                var filePaths = Directory.EnumerateFiles(args.Path, "*", new EnumerationOptions { IgnoreInaccessible = true });
+                IEnumerable<string> filePaths;
+                try
+                {
+                    filePaths = Directory.EnumerateFiles(args.Path, "*", new EnumerationOptions { IgnoreInaccessible = true });
+                }
+                catch (IOException)
+                {
+                    return null;
+                }
+
                 if (filePaths.Any(f => f.EndsWith(PlaylistXmlSaver.DefaultPlaylistFilename, StringComparison.OrdinalIgnoreCase)))
                 {
                     return new Playlist

Emby.Server.Implementations/Library/UserDataManager.cs

@@ -247,6 +247,103 @@ namespace Emby.Server.Implementations.Library
             return result;
         }
 
+        /// <inheritdoc />
+        public VersionResumeData? GetResumeUserData(User user, BaseItem item)
+        {
+            return GetResumeUserDataBatch([item], user).GetValueOrDefault(item.Id);
+        }
+
+        /// <inheritdoc />
+        public IReadOnlyDictionary<Guid, VersionResumeData> GetResumeUserDataBatch(IReadOnlyList<BaseItem> items, User user)
+        {
+            ArgumentNullException.ThrowIfNull(user);
+
+            var result = new Dictionary<Guid, VersionResumeData>();
+
+            // Candidate primaries: a directly queried version (PrimaryVersionId set) keeps its own data.
+            // Linked alternates are already known in memory; only the local-alternate existence check
+            // would otherwise hit the database (one query per item via Video.HasLocalAlternateVersions),
+            // so collect those ids and resolve them all in a single query below.
+            List<Video>? candidates = null;
+            List<Guid>? localProbeIds = null;
+            foreach (var item in items)
+            {
+                if (item is not Video video || video.PrimaryVersionId.HasValue)
+                {
+                    continue;
+                }
+
+                (candidates ??= []).Add(video);
+
+                if (video.LinkedAlternateVersions.Length == 0)
+                {
+                    (localProbeIds ??= []).Add(video.Id);
+                }
+            }
+
+            if (candidates is null)
+            {
+                return result;
+            }
+
+            HashSet<Guid>? withLocalAlternates = null;
+            if (localProbeIds is not null)
+            {
+                using var dbContext = _repository.CreateDbContext();
+                withLocalAlternates = dbContext.LinkedChildren
+                    .Where(lc => lc.ChildType == Jellyfin.Database.Implementations.Entities.LinkedChildType.LocalAlternateVersion
+                        && localProbeIds.Contains(lc.ParentId))
+                    .Select(lc => lc.ParentId)
+                    .Distinct()
+                    .ToHashSet();
+            }
+
+            List<(Guid PrimaryId, IReadOnlyList<Video> Versions)>? versionGroups = null;
+            List<BaseItem>? allVersions = null;
+
+            foreach (var video in candidates)
+            {
+                // Only items that actually have alternate versions aggregate over them.
+                if (video.LinkedAlternateVersions.Length == 0
+                    && (withLocalAlternates is null || !withLocalAlternates.Contains(video.Id)))
+                {
+                    continue;
+                }
+
+                var versions = video.GetAllVersions();
+                if (versions.Count < 2)
+                {
+                    continue;
+                }
+
+                (versionGroups ??= []).Add((video.Id, versions));
+                (allVersions ??= []).AddRange(versions);
+            }
+
+            if (versionGroups is null)
+            {
+                return result;
+            }
+
+            var userDataByVersion = GetUserDataBatch(allVersions!.DistinctBy(i => i.Id).ToList(), user);
+
+            foreach (var (primaryId, versions) in versionGroups)
+            {
+                // Consider both in-progress and completed versions so a finished alternate still marks the primary as played.
+                var resumeVersion = VersionPlaybackSelector.SelectMostRecentlyPlayed(
+                    versions,
+                    version => userDataByVersion.GetValueOrDefault(version.Id),
+                    data => data.PlaybackPositionTicks > 0 || data.Played);
+
+                if (resumeVersion is not null)
+                {
+                    result[primaryId] = new VersionResumeData(resumeVersion.Id, userDataByVersion[resumeVersion.Id]);
+                }
+            }
+
+            return result;
+        }
+
         /// <summary>
         /// Gets the internal key.
         /// </summary>
@@ -281,6 +378,10 @@ namespace Emby.Server.Implementations.Library
             var dto = GetUserItemDataDto(userData, item.Id);
 
             item.FillUserDataDtoValues(dto, userData, itemDto, user, options);
+
+            // For an item with alternate versions, surface the most recently played version's resume point.
+            GetResumeUserData(user, item)?.ApplyTo(dto);
+
             return dto;
         }
 
@@ -385,5 +486,41 @@ namespace Emby.Server.Implementations.Library
 
             return playedToCompletion;
         }
+
+        /// <inheritdoc />
+        public void ResetPlaybackStreamSelections(User user, BaseItem item)
+        {
+            ArgumentNullException.ThrowIfNull(user);
+            ArgumentNullException.ThrowIfNull(item);
+
+            using var dbContext = _repository.CreateDbContext();
+            var rows = dbContext.UserData
+                .Where(e => e.ItemId == item.Id && e.UserId == user.Id
+                            && (e.AudioStreamIndex != null || e.SubtitleStreamIndex != null))
+                .ToList();
+
+            if (rows.Count == 0)
+            {
+                return;
+            }
+
+            foreach (var row in rows)
+            {
+                row.AudioStreamIndex = null;
+                row.SubtitleStreamIndex = null;
+            }
+
+            dbContext.SaveChanges();
+
+            var cacheKey = GetCacheKey(user.InternalId, item.Id);
+            if (_cache.TryGet(cacheKey, out var cached))
+            {
+                cached.AudioStreamIndex = null;
+                cached.SubtitleStreamIndex = null;
+                _cache.AddOrUpdate(cacheKey, cached);
+            }
+
+            item.UserData = dbContext.UserData.Where(e => e.ItemId == item.Id).AsNoTracking().ToArray();
+        }
     }
 }

Emby.Server.Implementations/Localization/Core/da.json

@@ -9,7 +9,7 @@
     "Favorites": "Favoritter",
     "Folders": "Mapper",
     "Genres": "Genrer",
-    "HeaderContinueWatching": "Fortsæt afspilning",
+    "HeaderContinueWatching": "Fortsæt med at se",
     "HeaderFavoriteEpisodes": "Yndlingsafsnit",
     "HeaderFavoriteShows": "Yndlingsserier",
     "HeaderLiveTV": "Live-TV",
@@ -65,7 +65,7 @@
     "TaskDownloadMissingSubtitlesDescription": "Søger på internettet efter manglende undertekster baseret på metadata-konfigurationen.",
     "TaskDownloadMissingSubtitles": "Hent manglende undertekster",
     "TaskUpdatePluginsDescription": "Henter og installerer opdateringer for plugins, som er konfigurerede til at blive opdateret automatisk.",
-    "TaskUpdatePlugins": "Opdater plugins",
+    "TaskUpdatePlugins": "Opdatér plugins",
     "TaskCleanLogsDescription": "Sletter log-filer som er mere end {0} dage gamle.",
     "TaskCleanLogs": "Ryd log-mappe",
     "TaskRefreshLibraryDescription": "Scanner dit mediebibliotek for nye filer og opdateret metadata.",
@@ -79,10 +79,10 @@
     "TaskRefreshChapterImages": "Udtræk kapitelbilleder",
     "TaskRefreshChapterImagesDescription": "Laver miniaturebilleder for videoer, der har kapitler.",
     "TaskRefreshChannelsDescription": "Opdaterer information for internetkanaler.",
-    "TaskRefreshChannels": "Opdater kanaler",
+    "TaskRefreshChannels": "Opdatér kanaler",
     "TaskCleanTranscodeDescription": "Fjerner omkodningsfiler, som er mere end 1 dag gamle.",
     "TaskCleanTranscode": "Tøm omkodningsmappen",
-    "TaskRefreshPeople": "Opdater personer",
+    "TaskRefreshPeople": "Opdatér personer",
     "TaskRefreshPeopleDescription": "Opdaterer metadata for skuespillere og instruktører i dit mediebibliotek.",
     "TaskCleanActivityLogDescription": "Sletter linjer i aktivitetsloggen ældre end den konfigurerede alder.",
     "TaskCleanActivityLog": "Ryd aktivitetslog",
@@ -90,7 +90,7 @@
     "Forced": "Tvunget",
     "Default": "Standard",
     "TaskOptimizeDatabaseDescription": "Komprimerer databasen for at frigøre plads. Denne handling køres efter at have scannet mediebiblioteket, eller efter at have lavet ændringer til databasen.",
-    "TaskOptimizeDatabase": "Optimer database",
+    "TaskOptimizeDatabase": "Optimér database",
     "TaskKeyframeExtractorDescription": "Udtrækker rammer fra videofiler for at lave mere præcise HLS-playlister. Denne opgave kan tage lang tid.",
     "TaskKeyframeExtractor": "Udtræk nøglerammer",
     "External": "Ekstern",
@@ -99,7 +99,7 @@
     "TaskRefreshTrickplayImagesDescription": "Laver trickplay-billeder for videoer i aktiverede biblioteker.",
     "TaskAudioNormalizationDescription": "Skanner filer for data vedrørende lydnormalisering.",
     "TaskAudioNormalization": "Lydnormalisering",
-    "TaskDownloadMissingLyricsDescription": "Søger på internettet efter manglende sangtekster baseret på metadata-konfigurationen",
+    "TaskDownloadMissingLyricsDescription": "Download sangtekster",
     "TaskDownloadMissingLyrics": "Hent manglende sangtekster",
     "TaskExtractMediaSegments": "Scan for mediesegmenter",
     "TaskMoveTrickplayImages": "Migrer billedelokationer for trickplay-billeder",

Emby.Server.Implementations/Localization/Core/en_US.json

@@ -1,64 +0,0 @@
-{
-    "AppDeviceValues": "App: {0}, Device: {1}",
-    "Artists": "Artists",
-    "AuthenticationSucceededWithUserName": "{0} successfully authenticated",
-    "Books": "Books",
-    "ChapterNameValue": "Chapter {0}",
-    "Collections": "Collections",
-    "Default": "Default",
-    "External": "External",
-    "FailedLoginAttemptWithUserName": "Failed login attempt from {0}",
-    "Favorites": "Favorites",
-    "Folders": "Folders",
-    "Forced": "Forced",
-    "Genres": "Genres",
-    "HeaderContinueWatching": "Continue Watching",
-    "HeaderFavoriteEpisodes": "Favorite Episodes",
-    "HeaderFavoriteShows": "Favorite Shows",
-    "HeaderLiveTV": "Live TV",
-    "HeaderNextUp": "Next Up",
-    "HearingImpaired": "Hearing Impaired",
-    "HomeVideos": "Home Videos",
-    "Inherit": "Inherit",
-    "LabelIpAddressValue": "IP address: {0}",
-    "LabelRunningTimeValue": "Running time: {0}",
-    "Latest": "Latest",
-    "LyricDownloadFailureFromForItem": "Lyrics failed to download from {0} for {1}",
-    "MixedContent": "Mixed content",
-    "Movies": "Movies",
-    "Music": "Music",
-    "MusicVideos": "Music Videos",
-    "NameInstallFailed": "{0} installation failed",
-    "NameSeasonNumber": "Season {0}",
-    "NameSeasonUnknown": "Season Unknown",
-    "NewVersionIsAvailable": "A new version of Jellyfin Server is available for download.",
-    "NotificationOptionApplicationUpdateAvailable": "Application update available",
-    "NotificationOptionApplicationUpdateInstalled": "Application update installed",
-    "NotificationOptionAudioPlayback": "Audio playback started",
-    "NotificationOptionAudioPlaybackStopped": "Audio playback stopped",
-    "NotificationOptionCameraImageUploaded": "Camera image uploaded",
-    "NotificationOptionInstallationFailed": "Installation failure",
-    "NotificationOptionNewLibraryContent": "New content added",
-    "NotificationOptionPluginError": "Plugin failure",
-    "NotificationOptionPluginInstalled": "Plugin installed",
-    "NotificationOptionPluginUninstalled": "Plugin uninstalled",
-    "NotificationOptionPluginUpdateInstalled": "Plugin update installed",
-    "NotificationOptionServerRestartRequired": "Server restart required",
-    "NotificationOptionTaskFailed": "Scheduled task failure",
-    "NotificationOptionUserLockedOut": "User locked out",
-    "NotificationOptionVideoPlayback": "Video playback started",
-    "NotificationOptionVideoPlaybackStopped": "Video playback stopped",
-    "Original": "Original",
-    "Photos": "Photos",
-    "PluginInstalledWithName": "{0} was installed",
-    "PluginUninstalledWithName": "{0} was uninstalled",
-    "PluginUpdatedWithName": "{0} was updated",
-    "ScheduledTaskFailedWithName": "{0} failed",
-    "Shows": "Shows",
-    "StartupEmbyServerIsLoading": "Jellyfin Server is loading. Please try again shortly.",
-    "SubtitleDownloadFailureFromForItem": "Subtitles failed to download from {0} to {1}",
-    "TvShows": "TV Shows",
-    "Undefined": "Undefined",
-    "UserCreatedWithName": "User {0} has been created",
-    "UserDeletedWithName": "User {0} has been deleted"
-}

Emby.Server.Implementations/Localization/Core/gl.json

@@ -106,5 +106,6 @@
     "TaskRefreshTrickplayImages": "Xerar miniaturas de previsualización",
     "TaskAudioNormalizationDescription": "Escanea ficheiros á procura de datos de normalización de volume.",
     "CleanupUserDataTask": "Tarefa de limpeza de datos dos usuarios",
-    "CleanupUserDataTaskDescription": "Limpa todos os datos do usuario (estado de visualización, de favorito etc.) dos medios ausentes polo menos 90 días."
+    "CleanupUserDataTaskDescription": "Limpa todos os datos do usuario (estado de visualización, de favorito etc.) dos medios ausentes polo menos 90 días.",
+    "Original": "Orixinal"
 }

Emby.Server.Implementations/Localization/Core/he.json

@@ -106,5 +106,7 @@
     "TaskExtractMediaSegmentsDescription": "מחלץ חלקי מדיה מתוספים המאפשרים זאת.",
     "TaskMoveTrickplayImagesDescription": "הזזת קבצי Trickplay קיימים בהתאם להגדרות הספרייה.",
     "CleanupUserDataTaskDescription": "ניקוי כל המידע של המשתמש (מצב צפייה, מועדפים וכו) ממדיה שאינה קיימת מעל 90 יום.",
-    "CleanupUserDataTask": "משימת ניקוי מידע משתמש"
+    "CleanupUserDataTask": "משימת ניקוי מידע משתמש",
+    "LyricDownloadFailureFromForItem": "הורדת המילים מ-{0} עבור {1} נכשלה",
+    "Original": "מקור"
 }

Emby.Server.Implementations/Localization/Core/is.json

@@ -103,5 +103,8 @@
     "TaskDownloadMissingLyrics": "Sækja söngtexta sem vantar",
     "TaskExtractMediaSegments": "Skönnun efnishluta",
     "CleanupUserDataTask": "Hreinsun notendagagna",
-    "CleanupUserDataTaskDescription": "Hreinsar öll notendagögn (spilunarstöðu, uppáhöld o.s.frv.) um gögn sem hafa ekki verið til staðar í að lámarki 90 daga."
+    "CleanupUserDataTaskDescription": "Hreinsar öll notendagögn (spilunarstöðu, uppáhöld o.s.frv.) um gögn sem hafa ekki verið til staðar í að lámarki 90 daga.",
+    "LyricDownloadFailureFromForItem": "Ekki tókst að niðurhala texta frá {0} fyrir {1}",
+    "Original": "Upprunaleg",
+    "TaskExtractMediaSegmentsDescription": "Sækir myndbúta úr viðbótum þar sem MediaSegment er virkt."
 }

Emby.Server.Implementations/Localization/Core/ja.json

@@ -106,5 +106,7 @@
     "TaskDownloadMissingLyrics": "失われた歌詞をダウンロード",
     "TaskExtractMediaSegmentsDescription": "MediaSegment 対応プラグインからメディア セグメントを抽出または取得します。",
     "CleanupUserDataTask": "ユーザーデータのクリーンアップタスク",
-    "CleanupUserDataTaskDescription": "90日以上存在しないメディアに対して、視聴状態やお気に入り状態などのユーザーデータをすべて削除します。"
+    "CleanupUserDataTaskDescription": "90日以上存在しないメディアに対して、視聴状態やお気に入り状態などのユーザーデータをすべて削除します。",
+    "LyricDownloadFailureFromForItem": "歌詞",
+    "Original": "オリジナル"
 }

Emby.Server.Implementations/Localization/Core/ko.json

@@ -106,5 +106,7 @@
     "TaskDownloadMissingLyrics": "누락된 가사 다운로드",
     "TaskDownloadMissingLyricsDescription": "가사 다운로드",
     "CleanupUserDataTask": "사용자 데이터 정리 작업",
-    "CleanupUserDataTaskDescription": "최소 90일 이상 존재하지 않는 미디어에 대한 사용자 데이터(시청 상태, 즐겨찾기 등)를 정리합니다."
+    "CleanupUserDataTaskDescription": "최소 90일 이상 존재하지 않는 미디어에 대한 사용자 데이터(시청 상태, 즐겨찾기 등)를 정리합니다.",
+    "LyricDownloadFailureFromForItem": "{1}에 대한 가사를 {0}에서 다운로드하지 못했습니다",
+    "Original": "원본"
 }

Emby.Server.Implementations/Localization/Core/si.json

@@ -1 +1,15 @@
-{}
+{
+    "AppDeviceValues": "ඇප්: {0}, උපාංග: {1}",
+    "Artists": "කලාකරුවන්",
+    "AuthenticationSucceededWithUserName": "{0} සාර්ථකව තහවුරු කරන ලදී",
+    "Books": "පොත්",
+    "ChapterNameValue": "{0} වෙනි පරිච්ඡේදය",
+    "Collections": "සංහිතා",
+    "Default": "පෙරනිමි",
+    "External": "බාහිර",
+    "FailedLoginAttemptWithUserName": "{0} වෙතින් සිදුකළ පිවිසීමේ උත්සාහය අසාර්ථක විය",
+    "Favorites": "ප්‍රියතමයන්",
+    "Folders": "ෆෝල්ඩර",
+    "Forced": "නියමිත",
+    "Genres": "ප්‍රභේද"
+}

Emby.Server.Implementations/Localization/Core/sq.json

@@ -106,5 +106,7 @@
     "TaskAudioNormalization": "Normalizimi i audios",
     "TaskAudioNormalizationDescription": "Skannon skedarët për të dhëna të normalizimit të audios.",
     "CleanupUserDataTaskDescription": "Pastron të gjitha të dhënat e përdorueseve (gjendja e shikimit, statusi i të preferuarave etj.) nga mediat që nuk janë më të pranishme për të paktën 90 ditë.",
-    "CleanupUserDataTask": "Veprim për pastrimin të dhënave të përdorueseve"
+    "CleanupUserDataTask": "Veprim për pastrimin të dhënave të përdorueseve",
+    "LyricDownloadFailureFromForItem": "Teksti i këngës nuk arriti të shkarkohej nga {0} për {1}",
+    "Original": "Origjinal"
 }

Emby.Server.Implementations/Localization/Core/sw.json

@@ -1 +1,5 @@
-{}
+{
+    "Artists": "Wasanii",
+    "Books": "Vitabu",
+    "Collections": "Mikusanyiko"
+}

Emby.Server.Implementations/Localization/Core/zh-HK.json

@@ -77,8 +77,8 @@
     "TaskCleanLogsDescription": "自動刪走超過 {0} 日嘅紀錄檔。",
     "TaskCleanLogs": "清理日誌資料夾",
     "TaskRefreshLibrary": "掃描媒體櫃",
-    "TaskRefreshChapterImagesDescription": "幫有章節嘅影片整返啲章節縮圖。",
-    "TaskRefreshChapterImages": "擷取章節圖片",
+    "TaskRefreshChapterImagesDescription": "幫有章節嘅影片整返啲章節預覽圖。",
+    "TaskRefreshChapterImages": "擷取章節圖像",
     "TaskCleanCacheDescription": "刪走系統已經唔再需要嘅快取檔案。",
     "TaskCleanCache": "清理快取（Cache）資料夾",
     "TasksChannelsCategory": "網路頻道",

Emby.Server.Implementations/Localization/LocalizationManager.cs

@@ -356,6 +356,27 @@ namespace Emby.Server.Implementations.Localization
         {
             ArgumentException.ThrowIfNullOrEmpty(rating);
 
+            // Some providers may list multiple ratings separated by '/' (e.g. "SE:15 / SE:15+ / SE:Från 15 år").
+            // Try each one in order and use the first that resolves.
+            var ratingValues = rating.Split('/', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+
+            foreach (var ratingValue in ratingValues)
+            {
+                var score = GetSingleRatingScore(ratingValue, countryCode);
+                if (score is not null)
+                {
+                    return score;
+                }
+            }
+
+            return null;
+        }
+
+        /// <summary>
+        /// Resolves a single rating value to a score.
+        /// </summary>
+        private ParentalRatingScore? GetSingleRatingScore(string rating, string? countryCode)
+        {
             // Handle unrated content
             if (_unratedValues.Contains(rating.AsSpan(), StringComparison.OrdinalIgnoreCase))
             {
@@ -566,11 +587,15 @@ namespace Emby.Server.Implementations.Localization
 
         private static string GetResourceFilename(string culture)
         {
-            var parts = culture.Split('-');
+            // Region codes may use a '-' (BCP-47, e.g. "pt-BR") or '_' (e.g. "es_419", "ar_SA") separator.
+            // Normalize the casing (lower-case language, upper-case region) while preserving the separator
+            // so the result matches the embedded resource file name, which is case-sensitive.
+            var separatorIndex = culture.IndexOfAny(['-', '_']);
 
-            if (parts.Length == 2)
+            if (separatorIndex > 0)
             {
-                culture = parts[0].ToLowerInvariant() + "-" + parts[1].ToUpperInvariant();
+                var separator = culture[separatorIndex];
+                culture = culture[..separatorIndex].ToLowerInvariant() + separator + culture[(separatorIndex + 1)..].ToUpperInvariant();
             }
             else
             {

Emby.Server.Implementations/Localization/Ratings/gr.json

@@ -10,21 +10,42 @@
             }
         },
         {
-            "ratingStrings": ["K12"],
+            "ratingStrings": ["K12", "K-12", "12"],
+            "ratingScore": {
+                "score": 12,
+                "subScore": null
+            }
+        },
+        {
+            "ratingStrings": ["K13", "K-13", "13"],
             "ratingScore": {
                 "score": 13,
                 "subScore": null
             }
         },
         {
-            "ratingStrings": ["K15"],
+            "ratingStrings": ["K15", "K-15", "15"],
             "ratingScore": {
                 "score": 15,
                 "subScore": null
             }
         },
         {
-            "ratingStrings": ["K18"],
+            "ratingStrings": ["K16", "K-16", "16"],
+            "ratingScore": {
+                "score": 16,
+                "subScore": null
+            }
+        },
+        {
+            "ratingStrings": ["K17", "K-17", "17"],
+            "ratingScore": {
+                "score": 17,
+                "subScore": null
+            }
+        },
+        {
+            "ratingStrings": ["K18", "K-18", "18", "18+"],
             "ratingScore": {
                 "score": 18,
                 "subScore": null

Emby.Server.Implementations/Localization/Ratings/se.json

@@ -10,7 +10,7 @@
             }
         },
         {
-            "ratingStrings": ["7"],
+            "ratingStrings": ["7", "7+", "7 År", "Från 7 år"],
             "ratingScore": {
                 "score": 7,
                 "subScore": null
@@ -31,7 +31,7 @@
             }
         },
         {
-            "ratingStrings": ["11"],
+            "ratingStrings": ["11", "11+", "11 År", "Från 11 år"],
             "ratingScore": {
                 "score": 11,
                 "subScore": null
@@ -45,11 +45,18 @@
             }
         },
         {
-            "ratingStrings": ["15"],
+            "ratingStrings": ["15", "15+", "15 År", "Från 15 år"],
             "ratingScore": {
                 "score": 15,
                 "subScore": null
             }
+        },
+        {
+            "ratingStrings": ["18", "18+", "Barnförbjuden", "Bfj"],
+            "ratingScore": {
+                "score": 18,
+                "subScore": null
+            }
         }
     ]
 }

Emby.Server.Implementations/ScheduledTasks/Tasks/OptimizeDatabaseTask.cs

@@ -3,6 +3,7 @@ using System.Collections.Generic;
 using System.Threading;
 using System.Threading.Tasks;
 using Jellyfin.Database.Implementations;
+using MediaBrowser.Controller.Library;
 using MediaBrowser.Model.Globalization;
 using MediaBrowser.Model.Tasks;
 using Microsoft.Extensions.Logging;
@@ -17,6 +18,7 @@ public class OptimizeDatabaseTask : IScheduledTask, IConfigurableScheduledTask
     private readonly ILogger<OptimizeDatabaseTask> _logger;
     private readonly ILocalizationManager _localization;
     private readonly IJellyfinDatabaseProvider _jellyfinDatabaseProvider;
+    private readonly ILibraryManager _libraryManager;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="OptimizeDatabaseTask" /> class.
@@ -24,14 +26,17 @@ public class OptimizeDatabaseTask : IScheduledTask, IConfigurableScheduledTask
     /// <param name="logger">Instance of the <see cref="ILogger"/> interface.</param>
     /// <param name="localization">Instance of the <see cref="ILocalizationManager"/> interface.</param>
     /// <param name="jellyfinDatabaseProvider">Instance of the JellyfinDatabaseProvider that can be used for provider specific operations.</param>
+    /// <param name="libraryManager">Instance of the <see cref="ILibraryManager"/> interface.</param>
     public OptimizeDatabaseTask(
         ILogger<OptimizeDatabaseTask> logger,
         ILocalizationManager localization,
-        IJellyfinDatabaseProvider jellyfinDatabaseProvider)
+        IJellyfinDatabaseProvider jellyfinDatabaseProvider,
+        ILibraryManager libraryManager)
     {
         _logger = logger;
         _localization = localization;
         _jellyfinDatabaseProvider = jellyfinDatabaseProvider;
+        _libraryManager = libraryManager;
     }
 
     /// <inheritdoc />
@@ -68,6 +73,15 @@ public class OptimizeDatabaseTask : IScheduledTask, IConfigurableScheduledTask
     /// <inheritdoc />
     public async Task ExecuteAsync(IProgress<double> progress, CancellationToken cancellationToken)
     {
+        // Vacuuming/checkpointing requires an exclusive lock on the database. Running it while a library scan is in
+        // progress causes both operations to contend for the database and can stall the scan, so defer optimization
+        // until no scan is running. The task will run again on its next trigger.
+        if (_libraryManager.IsScanRunning)
+        {
+            _logger.LogInformation("Skipping database optimization because a library scan is currently running.");
+            return;
+        }
+
         _logger.LogInformation("Optimizing and vacuuming jellyfin.db...");
 
         try

Emby.Server.Implementations/ScheduledTasks/Tasks/PeopleValidationTask.cs

@@ -4,11 +4,18 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
+using Jellyfin.Data.Enums;
 using Jellyfin.Database.Implementations;
+using Jellyfin.Database.Implementations.Entities;
+using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Library;
+using MediaBrowser.Controller.Persistence;
+using MediaBrowser.Controller.Providers;
 using MediaBrowser.Model.Globalization;
+using MediaBrowser.Model.IO;
 using MediaBrowser.Model.Tasks;
 using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
 
 namespace Emby.Server.Implementations.ScheduledTasks.Tasks;
 
@@ -20,6 +27,9 @@ public class PeopleValidationTask : IScheduledTask, IConfigurableScheduledTask
     private readonly ILibraryManager _libraryManager;
     private readonly ILocalizationManager _localization;
     private readonly IDbContextFactory<JellyfinDbContext> _dbContextFactory;
+    private readonly IFileSystem _fileSystem;
+    private readonly ILogger<PeopleValidationTask> _logger;
+    private readonly IItemTypeLookup _itemTypeLookup;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="PeopleValidationTask" /> class.
@@ -27,11 +37,23 @@ public class PeopleValidationTask : IScheduledTask, IConfigurableScheduledTask
     /// <param name="libraryManager">Instance of the <see cref="ILibraryManager"/> interface.</param>
     /// <param name="localization">Instance of the <see cref="ILocalizationManager"/> interface.</param>
     /// <param name="dbContextFactory">Instance of the <see cref="IDbContextFactory{TContext}"/> interface.</param>
-    public PeopleValidationTask(ILibraryManager libraryManager, ILocalizationManager localization, IDbContextFactory<JellyfinDbContext> dbContextFactory)
+    /// <param name="fileSystem">Instance of the <see cref="IFileSystem"/> interface.</param>
+    /// <param name="logger">Instance of the <see cref="ILogger{PeopleValidationTask}"/> interface.</param>
+    /// <param name="itemTypeLookup">Instance of the <see cref="IItemTypeLookup"/> interface.</param>
+    public PeopleValidationTask(
+        ILibraryManager libraryManager,
+        ILocalizationManager localization,
+        IDbContextFactory<JellyfinDbContext> dbContextFactory,
+        IFileSystem fileSystem,
+        ILogger<PeopleValidationTask> logger,
+        IItemTypeLookup itemTypeLookup)
     {
         _libraryManager = libraryManager;
         _localization = localization;
         _dbContextFactory = dbContextFactory;
+        _fileSystem = fileSystem;
+        _logger = logger;
+        _itemTypeLookup = itemTypeLookup;
     }
 
     /// <inheritdoc />
@@ -71,13 +93,19 @@ public class PeopleValidationTask : IScheduledTask, IConfigurableScheduledTask
     /// <inheritdoc />
     public async Task ExecuteAsync(IProgress<double> progress, CancellationToken cancellationToken)
     {
-        IProgress<double> subProgress = new Progress<double>((val) => progress.Report(val / 2));
-        await _libraryManager.ValidatePeopleAsync(subProgress, cancellationToken).ConfigureAwait(false);
+        // People validation performs heavy database writes that contend with an active library scan.
+        // Defer it until the scan has finished; the task will run again on its next trigger.
+        if (_libraryManager.IsScanRunning)
+        {
+            _logger.LogInformation("Skipping people validation because a library scan is currently running.");
+            return;
+        }
 
-        subProgress = new Progress<double>((val) => progress.Report((val / 2) + 50));
+        // Phase 1: Deduplicate and remove orphaned people (0-33%)
         var context = await _dbContextFactory.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);
         await using (context.ConfigureAwait(false))
         {
+            IProgress<double> subProgress = new Progress<double>((val) => progress.Report(val / 3));
             var dupQuery = context.Peoples
                     .GroupBy(e => new { e.Name, e.PersonType })
                     .Where(e => e.Count() > 1)
@@ -123,7 +151,113 @@ public class PeopleValidationTask : IScheduledTask, IConfigurableScheduledTask
                 ArrayPool<Guid[]>.Shared.Return(buffer);
             }
 
+            var peopleToDelete = await context.Peoples
+                .Where(p => !context.PeopleBaseItemMap.Any(m => m.PeopleId.Equals(p.Id)))
+                .ExecuteDeleteAsync(cancellationToken)
+                .ConfigureAwait(false);
+            _logger.LogInformation("Removed {Count} orphaned people.", peopleToDelete);
+
             subProgress.Report(100);
         }
+
+        // Phase 2: Validate people (33-66%). Runs after orphaned PeopleBaseItemMap entries are
+        // cleaned up above, so dead people are removed in a single pass instead of requiring a second run.
+        IProgress<double> validateProgress = new Progress<double>((val) => progress.Report((val / 3) + 33));
+        await _libraryManager.ValidatePeopleAsync(validateProgress, cancellationToken).ConfigureAwait(false);
+
+        // Phase 3: Refresh images for people missing them (66-100%)
+        IProgress<double> refreshProgress = new Progress<double>((val) => progress.Report((val / 3) + 66));
+        await RefreshPeopleImagesAsync(refreshProgress, cancellationToken).ConfigureAwait(false);
+
+        progress.Report(100);
+    }
+
+    private async Task RefreshPeopleImagesAsync(IProgress<double> progress, CancellationToken cancellationToken)
+    {
+        var thirtyDaysAgo = DateTime.UtcNow.AddDays(-30);
+        var personTypeName = _itemTypeLookup.BaseItemKindNames[BaseItemKind.Person];
+
+        var context = await _dbContextFactory.CreateDbContextAsync(cancellationToken).ConfigureAwait(false);
+        await using (context.ConfigureAwait(false))
+        {
+            const int PartitionSize = 100;
+
+            var numPeople = await context.BaseItems
+                .AsNoTracking()
+                .Where(b => b.Type == personTypeName)
+                .Where(b => b.DateLastRefreshed == null || b.DateLastRefreshed < thirtyDaysAgo)
+                .Where(b =>
+                    !b.Images!.Any(i => i.ImageType == ImageInfoImageType.Primary) ||
+                    string.IsNullOrEmpty(b.Overview))
+                .CountAsync(cancellationToken)
+                .ConfigureAwait(false);
+
+            _logger.LogDebug("Found {Count} people needing image/overview refresh", numPeople);
+
+            if (numPeople == 0)
+            {
+                progress.Report(100);
+                return;
+            }
+
+            var numComplete = 0;
+            var numRefreshed = 0;
+
+            await foreach (var entry in context.BaseItems
+                .AsNoTracking()
+                .Where(b => b.Type == personTypeName)
+                .Where(b => b.DateLastRefreshed == null || b.DateLastRefreshed < thirtyDaysAgo)
+                .Where(b =>
+                    !b.Images!.Any(i => i.ImageType == ImageInfoImageType.Primary) ||
+                    string.IsNullOrEmpty(b.Overview))
+                .OrderBy(b => b.Id)
+                .WithPartitionProgress(partition => _logger.LogDebug("Processing people partition {Partition}", partition))
+                .PartitionEagerAsync(PartitionSize, cancellationToken)
+                .WithCancellation(cancellationToken)
+                .ConfigureAwait(false))
+            {
+                if (await RefreshPersonAsync(entry.Id, cancellationToken).ConfigureAwait(false))
+                {
+                    numRefreshed++;
+                }
+
+                numComplete++;
+                progress.Report(100.0 * numComplete / numPeople);
+            }
+
+            _logger.LogInformation("Refreshed metadata for {Count} people missing images or overview", numRefreshed);
+        }
+    }
+
+    private async Task<bool> RefreshPersonAsync(Guid personId, CancellationToken cancellationToken)
+    {
+        try
+        {
+            if (_libraryManager.GetItemById(personId) is not Person item)
+            {
+                return false;
+            }
+
+            var hasImage = item.HasImage(MediaBrowser.Model.Entities.ImageType.Primary);
+            var hasOverview = !string.IsNullOrEmpty(item.Overview);
+
+            var options = new MetadataRefreshOptions(new DirectoryService(_fileSystem))
+            {
+                ImageRefreshMode = hasImage ? MetadataRefreshMode.ValidationOnly : MetadataRefreshMode.Default,
+                MetadataRefreshMode = hasOverview ? MetadataRefreshMode.ValidationOnly : MetadataRefreshMode.Default
+            };
+
+            await item.RefreshMetadata(options, cancellationToken).ConfigureAwait(false);
+            return true;
+        }
+        catch (OperationCanceledException)
+        {
+            throw;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Error refreshing images for person {PersonId}", personId);
+            return false;
+        }
     }
 }

Emby.Server.Implementations/Session/SessionManager.cs

@@ -343,6 +343,10 @@ namespace Emby.Server.Implementations.Session
                     _activeLiveStreamSessions.TryRemove(liveStreamId, out _);
                 }
             }
+            else
+            {
+                liveStreamNeedsToBeClosed = true;
+            }
 
             if (liveStreamNeedsToBeClosed)
             {
@@ -725,6 +729,31 @@ namespace Emby.Server.Implementations.Session
             return item;
         }
 
+        /// <summary>
+        /// Resolves the item whose user data (playback position, played status) should be updated
+        /// for a playback report. When an alternate version is played the client reports the displayed
+        /// item as <c>ItemId</c> and the played version as <c>MediaSourceId</c>.
+        /// </summary>
+        /// <param name="libraryItem">The now playing (displayed) item.</param>
+        /// <param name="mediaSourceId">The reported media source id.</param>
+        /// <returns>The item to track progress against.</returns>
+        private BaseItem GetProgressItem(BaseItem libraryItem, string mediaSourceId)
+        {
+            if (libraryItem is Video libraryVideo
+                && !string.IsNullOrEmpty(mediaSourceId)
+                && Guid.TryParse(mediaSourceId, out var mediaSourceItemId)
+                && !mediaSourceItemId.Equals(libraryVideo.Id))
+            {
+                var versionItem = libraryVideo.GetAlternateVersion(mediaSourceItemId);
+                if (versionItem is not null)
+                {
+                    return versionItem;
+                }
+            }
+
+            return libraryItem;
+        }
+
         /// <summary>
         /// Used to report that playback has started for an item.
         /// </summary>
@@ -756,9 +785,10 @@ namespace Emby.Server.Implementations.Session
 
             if (libraryItem is not null)
             {
+                var progressItem = GetProgressItem(libraryItem, info.MediaSourceId);
                 foreach (var user in users)
                 {
-                    OnPlaybackStart(user, libraryItem);
+                    OnPlaybackStart(user, progressItem);
                 }
             }
 
@@ -890,9 +920,10 @@ namespace Emby.Server.Implementations.Session
             // only update saved user data on actual check-ins, not automated ones
             if (libraryItem is not null && !isAutomated)
             {
+                var progressItem = GetProgressItem(libraryItem, info.MediaSourceId);
                 foreach (var user in users)
                 {
-                    OnPlaybackProgress(user, libraryItem, info);
+                    OnPlaybackProgress(user, progressItem, info);
                 }
             }
 
@@ -952,6 +983,20 @@ namespace Emby.Server.Implementations.Session
             if (changed)
             {
                 _userDataManager.SaveUserData(user, item, data, UserDataSaveReason.PlaybackProgress, CancellationToken.None);
+
+                // A completed version marks every alternate version played and clears their resume points, so the
+                // whole movie leaves Continue Watching and reads as watched everywhere. (Per-version resume positions
+                // only persist while nothing has been completed yet.)
+                if (data.Played == true && item is Video playedVideo)
+                {
+                    playedVideo.PropagatePlayedState(user, true);
+                }
+            }
+
+            if ((!user.RememberAudioSelections && info.AudioStreamIndex.HasValue)
+                || (!user.RememberSubtitleSelections && info.SubtitleStreamIndex.HasValue))
+            {
+                _userDataManager.ResetPlaybackStreamSelections(user, item);
             }
         }
 
@@ -1083,9 +1128,10 @@ namespace Emby.Server.Implementations.Session
 
             if (libraryItem is not null)
             {
+                var progressItem = GetProgressItem(libraryItem, info.MediaSourceId);
                 foreach (var user in users)
                 {
-                    playedToCompletion = OnPlaybackStopped(user, libraryItem, info.PositionTicks, info.Failed);
+                    playedToCompletion = OnPlaybackStopped(user, progressItem, info.PositionTicks, info.Failed);
                 }
             }
 
@@ -1138,6 +1184,14 @@ namespace Emby.Server.Implementations.Session
 
             _userDataManager.SaveUserData(user, item, data, UserDataSaveReason.PlaybackFinished, CancellationToken.None);
 
+            // A completed version marks every alternate version played and clears their resume points, so the
+            // whole movie leaves Continue Watching and reads as watched everywhere. (Per-version resume positions
+            // only persist while nothing has been completed yet.)
+            if (data.Played == true && item is Video playedVideo)
+            {
+                playedVideo.PropagatePlayedState(user, true);
+            }
+
             return playedToCompletion;
         }
 

Emby.Server.Implementations/Session/SessionWebSocketListener.cs

@@ -246,8 +246,21 @@ namespace Emby.Server.Implementations.Session
                     _logger.LogInformation("Lost {0} WebSockets.", lost.Count);
                     foreach (var webSocket in lost)
                     {
-                        // TODO: handle session relative to the lost webSocket
                         RemoveWebSocket(webSocket);
+
+                        // The connection stopped answering keep-alives, so a close frame will
+                        // never arrive and the pending receive loop would hang forever, keeping
+                        // the session (and e.g. its SyncPlay group membership) alive. Disposing
+                        // the connection aborts the receive loop, which raises Closed and lets
+                        // the session end normally.
+                        try
+                        {
+                            webSocket.Dispose();
+                        }
+                        catch (Exception exception)
+                        {
+                            _logger.LogWarning(exception, "Error disposing lost WebSocket from {RemoteEndPoint}.", webSocket.RemoteEndPoint);
+                        }
                     }
                 }
             }

Emby.Server.Implementations/TV/TVSeriesManager.cs

@@ -2,6 +2,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Linq;
 using Jellyfin.Data;
 using Jellyfin.Data.Enums;
@@ -136,11 +137,15 @@ namespace Emby.Server.Implementations.TV
 
                 if (nextEpisode is not null)
                 {
+                    // The last played date and the version that was actually played live on the version item's user data
+                    // The played state propagated to the sibling versions carries no date
+                    var (playedVersion, lastPlayedDate) = GetMostRecentlyPlayedVersion(result.LastWatched, user);
+                    nextEpisode = GetPreferredVersion(nextEpisode, result.LastWatched, playedVersion);
+
                     DateTime lastWatchedDate = DateTime.MinValue;
                     if (result.LastWatched is not null)
                     {
-                        var userData = _userDataManager.GetUserData(user, result.LastWatched);
-                        lastWatchedDate = userData?.LastPlayedDate ?? DateTime.MinValue.AddDays(1);
+                        lastWatchedDate = lastPlayedDate ?? DateTime.MinValue.AddDays(1);
                     }
 
                     nextUpList.Add((lastWatchedDate, nextEpisode));
@@ -152,11 +157,13 @@ namespace Emby.Server.Implementations.TV
 
                     if (nextPlayedEpisode is not null)
                     {
+                        var (playedVersion, lastPlayedDate) = GetMostRecentlyPlayedVersion(result.LastWatchedForRewatching, user);
+                        nextPlayedEpisode = GetPreferredVersion(nextPlayedEpisode, result.LastWatchedForRewatching, playedVersion);
+
                         DateTime rewatchLastWatchedDate = DateTime.MinValue;
                         if (result.LastWatchedForRewatching is not null)
                         {
-                            var userData = _userDataManager.GetUserData(user, result.LastWatchedForRewatching);
-                            rewatchLastWatchedDate = userData?.LastPlayedDate ?? DateTime.MinValue.AddDays(1);
+                            rewatchLastWatchedDate = lastPlayedDate ?? DateTime.MinValue.AddDays(1);
                         }
 
                         nextUpList.Add((rewatchLastWatchedDate, nextPlayedEpisode));
@@ -219,10 +226,13 @@ namespace Emby.Server.Implementations.TV
 
             if (nextEpisode is not null && !includeResumable)
             {
-                var userData = _userDataManager.GetUserData(user, nextEpisode);
-                if (userData?.PlaybackPositionTicks > 0)
+                // The resume progress may live on an alternate version
+                foreach (var version in nextEpisode.GetAllVersions())
                 {
-                    return null;
+                    if (_userDataManager.GetUserData(user, version)?.PlaybackPositionTicks > 0)
+                    {
+                        return null;
+                    }
                 }
             }
 
@@ -237,6 +247,74 @@ namespace Emby.Server.Implementations.TV
             return DetermineNextEpisode(result, user, includeSpecials, includeResumable: false, includePlayed: true);
         }
 
+        /// <summary>
+        /// Gets the version of the last watched episode that was actually played, together with its last played date.
+        /// The version that was played carries the most recent LastPlayedDate.
+        /// dates.
+        /// </summary>
+        /// <param name="lastWatched">The last watched episode (any version).</param>
+        /// <param name="user">The user.</param>
+        /// <returns>The played version and its last played date.</returns>
+        private (Video? PlayedVersion, DateTime? LastPlayedDate) GetMostRecentlyPlayedVersion(BaseItem? lastWatched, User user)
+        {
+            if (lastWatched is not Video lastWatchedVideo)
+            {
+                return (null, null);
+            }
+
+            var versions = lastWatchedVideo.GetAllVersions();
+            var userDataByVersion = _userDataManager.GetUserDataBatch(versions, user);
+
+            var playedVersion = VersionPlaybackSelector.SelectMostRecentlyPlayed(
+                versions,
+                version => userDataByVersion.GetValueOrDefault(version.Id),
+                data => data.LastPlayedDate.HasValue);
+
+            return (playedVersion, playedVersion is null ? null : userDataByVersion[playedVersion.Id].LastPlayedDate);
+        }
+
+        /// <summary>
+        /// When the last watched episode was played as an alternate version, prefer the next episode's version with the matching name,
+        /// so Next Up continues in the version the user has been watching instead of falling back to the primary.
+        /// </summary>
+        /// <param name="nextEpisode">The determined next episode (a primary).</param>
+        /// <param name="lastWatched">The last watched episode.</param>
+        /// <param name="playedVersion">The version of the last watched episode that was played.</param>
+        /// <returns>The matching version of the next episode, or the episode itself.</returns>
+        private Episode GetPreferredVersion(Episode nextEpisode, BaseItem? lastWatched, Video? playedVersion)
+        {
+            // No version preference, or the primary was played
+            if (lastWatched is not Video lastWatchedVideo
+                || playedVersion is null
+                || !playedVersion.PrimaryVersionId.HasValue)
+            {
+                return nextEpisode;
+            }
+
+            // Match by version name
+            var playedVersionId = playedVersion.Id.ToString("N", CultureInfo.InvariantCulture);
+            var playedVersionName = lastWatchedVideo.GetMediaSources(false)
+                .FirstOrDefault(source => string.Equals(source.Id, playedVersionId, StringComparison.OrdinalIgnoreCase))?.Name;
+
+            if (string.IsNullOrEmpty(playedVersionName))
+            {
+                return nextEpisode;
+            }
+
+            var matchingSource = nextEpisode.GetMediaSources(false)
+                .FirstOrDefault(source => string.Equals(source.Name, playedVersionName, StringComparison.OrdinalIgnoreCase));
+
+            if (matchingSource is not null
+                && Guid.TryParse(matchingSource.Id, out var matchingId)
+                && !matchingId.Equals(nextEpisode.Id)
+                && _libraryManager.GetItemById<Episode>(matchingId) is { } matchingVersion)
+            {
+                return matchingVersion;
+            }
+
+            return nextEpisode;
+        }
+
         private static string GetUniqueSeriesKey(Series series)
         {
             return series.GetPresentationUniqueKey();

Emby.Server.Implementations/Updates/InstallationManager.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Buffers;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.IO;
@@ -32,6 +33,8 @@ namespace Emby.Server.Implementations.Updates
     /// </summary>
     public class InstallationManager : IInstallationManager
     {
+        private static readonly SearchValues<char> InvalidPackageNameChars = SearchValues.Create([.. Path.GetInvalidFileNameChars(), '/', '\\']);
+
         /// <summary>
         /// The logger.
         /// </summary>
@@ -521,9 +524,27 @@ namespace Emby.Server.Implementations.Updates
                 return;
             }
 
+            if (!IsValidPackageDirectoryName(package.Name))
+            {
+                _logger.LogError("Refusing to install package with invalid name {PackageName}.", package.Name);
+                throw new InvalidDataException($"Plugin package name '{package.Name}' is not a valid directory name.");
+            }
+
             // Always override the passed-in target (which is a file) and figure it out again
             string targetDir = Path.Combine(_appPaths.PluginsPath, package.Name);
 
+            var pluginsRoot = Path.TrimEndingDirectorySeparator(Path.GetFullPath(_appPaths.PluginsPath));
+            var resolvedTarget = Path.GetFullPath(targetDir);
+            if (!resolvedTarget.StartsWith(pluginsRoot + Path.DirectorySeparatorChar, StringComparison.OrdinalIgnoreCase))
+            {
+                _logger.LogError(
+                    "Refusing to install package {PackageName}: resolved target {Resolved} is outside plugins directory {Root}.",
+                    package.Name,
+                    resolvedTarget,
+                    pluginsRoot);
+                throw new InvalidDataException($"Plugin package name '{package.Name}' resolves outside the plugins directory.");
+            }
+
             using var response = await _httpClientFactory.CreateClient(NamedClient.Default)
                 .GetAsync(new Uri(package.SourceUrl), cancellationToken).ConfigureAwait(false);
             response.EnsureSuccessStatusCode();
@@ -572,6 +593,26 @@ namespace Emby.Server.Implementations.Updates
             _pluginManager.ImportPluginFrom(targetDir);
         }
 
+        private static bool IsValidPackageDirectoryName(string? name)
+        {
+            if (string.IsNullOrWhiteSpace(name))
+            {
+                return false;
+            }
+
+            if (name.Equals(".", StringComparison.Ordinal) || name.Equals("..", StringComparison.Ordinal))
+            {
+                return false;
+            }
+
+            if (name.IndexOfAny(InvalidPackageNameChars) >= 0)
+            {
+                return false;
+            }
+
+            return true;
+        }
+
         private async Task<bool> InstallPackageInternal(InstallationInfo package, CancellationToken cancellationToken)
         {
             LocalPlugin? plugin = _pluginManager.Plugins.FirstOrDefault(p => p.Id.Equals(package.Id) && p.Version.Equals(package.Version))

Jellyfin.Api/Controllers/ImageController.cs

@@ -2049,7 +2049,7 @@ public class ImageController : BaseJellyfinApiController
             }
 
             // Check If-Modified-Since header for time-based validation
-            if (DateTime.TryParse(Request.Headers[HeaderNames.IfModifiedSince], out var ifModifiedSinceHeader))
+            if (DateTime.TryParse(Request.Headers[HeaderNames.IfModifiedSince], CultureInfo.InvariantCulture, out var ifModifiedSinceHeader))
             {
                 // Return 304 if the image has not been modified since the client's cached version
                 if (dateImageModified <= ifModifiedSinceHeader)

Jellyfin.Api/Controllers/ItemsController.cs

@@ -287,6 +287,8 @@ public class ItemsController : BaseJellyfinApiController
         QueryResult<BaseItem> result;
 
         Guid[] linkedChildAncestorIds = [];
+
+        includeItemTypes ??= [];
         if (includeItemTypes.Length == 1
             && (includeItemTypes[0] == BaseItemKind.BoxSet || includeItemTypes[0] == BaseItemKind.Playlist)
             && item is not BoxSet
@@ -314,6 +316,7 @@ public class ItemsController : BaseJellyfinApiController
         if (folder is IHasCollectionType hasCollectionType)
         {
             collectionType = hasCollectionType.CollectionType;
+            includeItemTypes = [.. includeItemTypes.Union(DtoExtensions.GetBaseItemKindsForCollectionType(collectionType))];
         }
 
         if (collectionType == CollectionType.playlists)
@@ -962,9 +965,15 @@ public class ItemsController : BaseJellyfinApiController
         var excludeItemIds = Array.Empty<Guid>();
         if (excludeActiveSessions)
         {
+            // NowPlayingItem.Id is the displayed/primary id, but resume queries surface the actually-played
+            // alternate version's own id. Expand each active session to every version id so an in-progress
+            // alternate is excluded too, instead of leaking back into the resume list.
             excludeItemIds = _sessionManager.Sessions
                 .Where(s => s.UserId.Equals(requestUserId) && s.NowPlayingItem is not null)
-                .Select(s => s.NowPlayingItem.Id)
+                .SelectMany(s => _libraryManager.GetItemById(s.NowPlayingItem.Id) is Video video
+                    ? video.GetAllVersions().Select(v => v.Id)
+                    : [s.NowPlayingItem.Id])
+                .Distinct()
                 .ToArray();
         }
 

Jellyfin.Api/Controllers/LiveTvController.cs

@@ -1002,9 +1002,7 @@ public class LiveTvController : BaseJellyfinApiController
     {
         if (!string.IsNullOrEmpty(pw))
         {
-            // TODO: remove ToLower when Convert.ToHexString supports lowercase
-            // Schedules Direct requires the hex to be lowercase
-            listingsProviderInfo.Password = Convert.ToHexString(SHA1.HashData(Encoding.UTF8.GetBytes(pw))).ToLowerInvariant();
+            listingsProviderInfo.Password = Convert.ToHexStringLower(SHA1.HashData(Encoding.UTF8.GetBytes(pw)));
         }
 
         return await _listingsManager.SaveListingProvider(listingsProviderInfo, validateLogin, validateListings).ConfigureAwait(false);

Jellyfin.Api/Controllers/TvShowsController.cs

@@ -277,8 +277,15 @@ public class TvShowsController : BaseJellyfinApiController
 
         if (startItemId.HasValue)
         {
+            // The start item may be an alternate version, which is not part of the episode listing; start from its primary episode instead.
+            var startId = startItemId.Value;
+            if (_libraryManager.GetItemById<Video>(startId)?.PrimaryVersionId is { } primaryVersionId)
+            {
+                startId = primaryVersionId;
+            }
+
             episodes = episodes
-                .SkipWhile(i => !startItemId.Value.Equals(i.Id))
+                .SkipWhile(i => !startId.Equals(i.Id))
                 .ToList();
         }
 

Jellyfin.Api/Extensions/DtoExtensions.cs

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using Jellyfin.Data.Enums;
 using MediaBrowser.Controller.Dto;
 using MediaBrowser.Model.Entities;
 
@@ -9,6 +10,37 @@ namespace Jellyfin.Api.Extensions;
 /// </summary>
 public static class DtoExtensions
 {
+    /// <summary>
+    /// Gets the BaseItemKind values associated with the specified CollectionType.
+    /// </summary>
+    /// <param name="collectionType">The collection type to map to BaseItemKind values.</param>
+    /// <returns>An array of BaseItemKind values that correspond to the collection type.</returns>
+    public static BaseItemKind[] GetBaseItemKindsForCollectionType(CollectionType? collectionType)
+    {
+        switch (collectionType)
+        {
+            case CollectionType.movies:
+                return [BaseItemKind.Movie];
+            case CollectionType.tvshows:
+                return [BaseItemKind.Series];
+            case CollectionType.music:
+                return [BaseItemKind.MusicAlbum, BaseItemKind.MusicArtist];
+            case CollectionType.musicvideos:
+                return [BaseItemKind.MusicVideo];
+            case CollectionType.books:
+                return [BaseItemKind.Book, BaseItemKind.AudioBook];
+            case CollectionType.boxsets:
+                return [BaseItemKind.BoxSet];
+            case CollectionType.homevideos:
+            case CollectionType.photos:
+                return [BaseItemKind.Video, BaseItemKind.Photo];
+            case CollectionType.folders:
+                return [];
+            default:
+                return [BaseItemKind.Video, BaseItemKind.Audio, BaseItemKind.Photo, BaseItemKind.Movie, BaseItemKind.Series];
+        }
+    }
+
     /// <summary>
     /// Add additional DtoOptions.
     /// </summary>

Jellyfin.Api/Helpers/StreamingHelpers.cs

@@ -144,6 +144,15 @@ public static class StreamingHelpers
             mediaSource = liveStreamInfo.Item1;
             state.DirectStreamProvider = liveStreamInfo.Item2;
 
+            // The requested live stream is no longer open. This commonly happens when a client keeps
+            // polling the HLS playlist (e.g. live.m3u8) after the stream was disposed because its
+            // consumer count dropped to zero. GetLiveStreamWithDirectStreamProvider returns a null
+            // MediaSource in that case, so return 404 instead of dereferencing it below.
+            if (mediaSource is null)
+            {
+                throw new ResourceNotFoundException($"The live stream with id {streamingRequest.LiveStreamId} could not be found or is no longer available.");
+            }
+
             // Cap the max bitrate when it is too high. This is usually due to ffmpeg is unable to probe the source liveTV streams' bitrate.
             if (mediaSource.FallbackMaxStreamingBitrate is not null && streamingRequest.VideoBitRate is not null)
             {

Jellyfin.Server.Implementations/Activity/ActivityManager.cs

@@ -56,11 +56,11 @@ public class ActivityManager : IActivityManager
         var dbContext = await _provider.CreateDbContextAsync().ConfigureAwait(false);
         await using (dbContext.ConfigureAwait(false))
         {
-            // TODO switch to LeftJoin in .NET 10.
-            var entries = from a in dbContext.ActivityLogs
-                          join u in dbContext.Users on a.UserId equals u.Id into ugj
-                          from u in ugj.DefaultIfEmpty()
-                          select new ExpandedActivityLog { ActivityLog = a, Username = u.Username };
+            var entries = dbContext.ActivityLogs.LeftJoin(
+                dbContext.Users,
+                a => a.UserId,
+                u => u.Id,
+                (a, u) => new ExpandedActivityLog { ActivityLog = a, Username = u == null ? null : u.Username });
 
             if (query.HasUserId is not null)
             {

Jellyfin.Server.Implementations/Devices/DeviceManager.cs

@@ -213,8 +213,10 @@ namespace Jellyfin.Server.Implementations.Devices
             var dbContext = await _dbProvider.CreateDbContextAsync().ConfigureAwait(false);
             await using (dbContext.ConfigureAwait(false))
             {
-                dbContext.Devices.Remove(device);
-                await dbContext.SaveChangesAsync().ConfigureAwait(false);
+                await dbContext.Devices
+                    .Where(d => d.Id == device.Id)
+                    .ExecuteDeleteAsync()
+                    .ConfigureAwait(false);
             }
         }
 

Jellyfin.Server.Implementations/FullSystemBackup/BackupService.cs

@@ -12,6 +12,7 @@ using Jellyfin.Database.Implementations;
 using Jellyfin.Server.Implementations.StorageHelpers;
 using Jellyfin.Server.Implementations.SystemBackupService;
 using MediaBrowser.Controller;
+using MediaBrowser.Controller.Library;
 using MediaBrowser.Controller.SystemBackupService;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.EntityFrameworkCore.Infrastructure;
@@ -33,6 +34,7 @@ public class BackupService : IBackupService
     private readonly IServerApplicationPaths _applicationPaths;
     private readonly IJellyfinDatabaseProvider _jellyfinDatabaseProvider;
     private readonly IHostApplicationLifetime _hostApplicationLifetime;
+    private readonly ILibraryManager _libraryManager;
     private static readonly JsonSerializerOptions _serializerSettings = new JsonSerializerOptions(JsonSerializerDefaults.General)
     {
         AllowTrailingCommas = true,
@@ -50,13 +52,15 @@ public class BackupService : IBackupService
     /// <param name="applicationPaths">The application paths.</param>
     /// <param name="jellyfinDatabaseProvider">The Jellyfin database Provider in use.</param>
     /// <param name="applicationLifetime">The SystemManager.</param>
+    /// <param name="libraryManager">Instance of the <see cref="ILibraryManager"/> interface.</param>
     public BackupService(
         ILogger<BackupService> logger,
         IDbContextFactory<JellyfinDbContext> dbProvider,
         IServerApplicationHost applicationHost,
         IServerApplicationPaths applicationPaths,
         IJellyfinDatabaseProvider jellyfinDatabaseProvider,
-        IHostApplicationLifetime applicationLifetime)
+        IHostApplicationLifetime applicationLifetime,
+        ILibraryManager libraryManager)
     {
         _logger = logger;
         _dbProvider = dbProvider;
@@ -64,6 +68,7 @@ public class BackupService : IBackupService
         _applicationPaths = applicationPaths;
         _jellyfinDatabaseProvider = jellyfinDatabaseProvider;
         _hostApplicationLifetime = applicationLifetime;
+        _libraryManager = libraryManager;
     }
 
     /// <inheritdoc/>
@@ -263,6 +268,14 @@ public class BackupService : IBackupService
     /// <inheritdoc/>
     public async Task<BackupManifestDto> CreateBackupAsync(BackupOptionsDto backupOptions)
     {
+        // Creating a backup runs a database optimization and reads the entire database under a transaction, both of
+        // which heavily contend with an active library scan and could capture an inconsistent database state.
+        if (_libraryManager.IsScanRunning)
+        {
+            _logger.LogWarning("Cannot create a backup while a library scan is running.");
+            throw new InvalidOperationException("Cannot create a backup while a library scan is running. Please try again once the scan has finished.");
+        }
+
         var manifest = new BackupManifest()
         {
             DateCreated = DateTime.UtcNow,

Jellyfin.Server.Implementations/Item/BaseItemRepository.QueryBuilding.cs

@@ -62,18 +62,21 @@ public sealed partial class BaseItemRepository
 
     private IQueryable<BaseItemEntity> ApplyGroupingFilter(JellyfinDbContext context, IQueryable<BaseItemEntity> dbQuery, InternalItemsQuery filter)
     {
-        // Collapse duplicates sharing a presentation key (e.g. alternate versions) by picking
-        // the min Id per group. Keep the grouped ids as an IQueryable sub-select; materializing
+        // Collapse duplicates sharing a presentation key (e.g. alternate versions), preferring the
+        // primary version (PrimaryVersionId is null) so detail pages and actions target it instead
+        // of an arbitrary alternate. Keep the grouped ids as an IQueryable sub-select; materializing
         // to a List would inline one bound parameter per id and hit SQLite's variable cap.
         var enableGroupByPresentationUniqueKey = EnableGroupByPresentationUniqueKey(filter);
         if (enableGroupByPresentationUniqueKey && filter.GroupBySeriesPresentationUniqueKey)
         {
-            var groupedIds = dbQuery.GroupBy(e => new { e.PresentationUniqueKey, e.SeriesPresentationUniqueKey }).Select(e => e.Min(x => x.Id));
+            var groupedIds = dbQuery.GroupBy(e => new { e.PresentationUniqueKey, e.SeriesPresentationUniqueKey })
+                .Select(g => g.Where(e => e.PrimaryVersionId == null).Min(e => (Guid?)e.Id) ?? g.Min(e => (Guid?)e.Id));
             dbQuery = context.BaseItems.AsNoTracking().Where(e => groupedIds.Contains(e.Id));
         }
         else if (enableGroupByPresentationUniqueKey)
         {
-            var groupedIds = dbQuery.GroupBy(e => e.PresentationUniqueKey).Select(e => e.Min(x => x.Id));
+            var groupedIds = dbQuery.GroupBy(e => e.PresentationUniqueKey)
+                .Select(g => g.Where(e => e.PrimaryVersionId == null).Min(e => (Guid?)e.Id) ?? g.Min(e => (Guid?)e.Id));
             dbQuery = context.BaseItems.AsNoTracking().Where(e => groupedIds.Contains(e.Id));
         }
         else if (filter.GroupBySeriesPresentationUniqueKey)

Jellyfin.Server.Implementations/Item/BaseItemRepository.TranslateQuery.cs

@@ -513,13 +513,17 @@ public sealed partial class BaseItemRepository
         if (filter.IsResumable.HasValue)
         {
             var hasSeries = filter.IncludeItemTypes.Contains(BaseItemKind.Series);
+            var userId = filter.User!.Id;
+            var isResumable = filter.IsResumable.Value;
+            var seriesTypeName = _itemTypeLookup.BaseItemKindNames[BaseItemKind.Series];
 
+            // In-progress user data rows; alternate versions track their own progress.
+            var inProgress = context.UserData
+                .Where(ud => ud.UserId == userId && ud.PlaybackPositionTicks > 0);
+
+            IQueryable<Guid>? resumableSeriesIds = null;
             if (hasSeries)
             {
-                var userId = filter.User!.Id;
-                var seriesTypeName = _itemTypeLookup.BaseItemKindNames[BaseItemKind.Series];
-                var isResumable = filter.IsResumable.Value;
-
                 // Aggregate per series in a single GROUP BY pass, instead of three full scans.
                 var seriesEpisodeStats = context.BaseItems
                     .AsNoTracking()
@@ -535,26 +539,44 @@ public sealed partial class BaseItemRepository
 
                 // A series is resumable if it has an in-progress episode,
                 // or if it has both played and unplayed episodes (partially watched).
-                var resumableSeriesIds = seriesEpisodeStats
+                resumableSeriesIds = seriesEpisodeStats
                     .Where(s => s.HasInProgress || (s.HasPlayed && s.HasUnplayed))
                     .Select(s => s.SeriesId);
+            }
 
-                // Non-series items: resumable if PlaybackPositionTicks > 0
-                var resumableItemIds = context.UserData
-                    .Where(ud => ud.UserId == userId && ud.PlaybackPositionTicks > 0)
-                    .Select(ud => ud.ItemId);
+            if (isResumable)
+            {
+                // Resume queries surface the version that was actually played, which may be an alternate.
+                // Match each version on its own progress rather than coalescing onto the primary.
+                var inProgressIds = inProgress.Select(ud => ud.ItemId);
 
-                baseQuery = baseQuery.Where(e =>
-                    (e.Type == seriesTypeName && resumableSeriesIds.Contains(e.Id) == isResumable)
-                    || (e.Type != seriesTypeName && resumableItemIds.Contains(e.Id) == isResumable));
+                baseQuery = hasSeries
+                    ? baseQuery.Where(e =>
+                        (e.Type == seriesTypeName && resumableSeriesIds!.Contains(e.Id))
+                        || (e.Type != seriesTypeName && inProgressIds.Contains(e.Id)))
+                    : baseQuery.Where(e => inProgressIds.Contains(e.Id));
+
+                // When several versions of the same item are in progress, keep only the most recently played one, use id as tiebreaker.
+                baseQuery = baseQuery.Where(e => e.Type == seriesTypeName || !context.BaseItems
+                    .Where(s => s.Id != e.Id && (s.PrimaryVersionId ?? s.Id) == (e.PrimaryVersionId ?? e.Id))
+                    .Any(s =>
+                        inProgress.Where(su => su.ItemId == s.Id).Max(su => su.LastPlayedDate)
+                            > inProgress.Where(eu => eu.ItemId == e.Id).Max(eu => eu.LastPlayedDate)
+                        || (inProgress.Where(su => su.ItemId == s.Id).Max(su => su.LastPlayedDate)
+                                == inProgress.Where(eu => eu.ItemId == e.Id).Max(eu => eu.LastPlayedDate)
+                            && s.Id.CompareTo(e.Id) < 0)));
             }
             else
             {
-                var resumableItemIds = context.UserData
-                    .Where(ud => ud.UserId == filter.User!.Id && ud.PlaybackPositionTicks > 0)
-                    .Select(ud => ud.ItemId);
-                var isResumable = filter.IsResumable.Value;
-                baseQuery = baseQuery.Where(e => resumableItemIds.Contains(e.Id) == isResumable);
+                // Not-resumable queries operate on primaries only.
+                var resumableMovieIds = inProgress
+                    .Join(context.BaseItems, ud => ud.ItemId, bi => bi.Id, (ud, bi) => bi.PrimaryVersionId ?? bi.Id);
+
+                baseQuery = hasSeries
+                    ? baseQuery.Where(e =>
+                        (e.Type == seriesTypeName && !resumableSeriesIds!.Contains(e.Id))
+                        || (e.Type != seriesTypeName && !resumableMovieIds.Contains(e.Id)))
+                    : baseQuery.Where(e => !resumableMovieIds.Contains(e.Id));
             }
         }
 
@@ -741,10 +763,13 @@ public sealed partial class BaseItemRepository
         }
         else if (filter.OwnerIds.Length == 0 && filter.ExtraTypes.Length == 0 && !filter.IncludeOwnedItems)
         {
-            // Exclude alternate versions and owned non-extra items from general queries.
-            // Alternate versions have PrimaryVersionId set (pointing to their primary).
+            // Exclude owned non-extra items from general queries.
             // Extras (trailers, etc.) have OwnerId set but also have ExtraType set - keep those.
-            baseQuery = baseQuery.Where(e => e.PrimaryVersionId == null && (e.OwnerId == null || e.ExtraType != null));
+            // Alternate versions (PrimaryVersionId set) are normally excluded too, but resume queries
+            // keep them so the actually-played version can surface instead of collapsing onto the primary.
+            baseQuery = filter.IsResumable == true
+                ? baseQuery.Where(e => e.OwnerId == null || e.ExtraType != null)
+                : baseQuery.Where(e => e.PrimaryVersionId == null && (e.OwnerId == null || e.ExtraType != null));
         }
 
         if (filter.OwnerIds.Length > 0)

Jellyfin.Server.Implementations/Item/BaseItemRepository.cs

@@ -167,6 +167,14 @@ public sealed partial class BaseItemRepository
             return false;
         }
 
+        // Resume queries surface the actually-played version (which may be an alternate sharing the
+        // primary's presentation key). The resumable filter already keeps one version per group, so
+        // presentation-key grouping must not collapse the surfaced version back onto the primary.
+        if (query.IsResumable == true)
+        {
+            return false;
+        }
+
         if (query.GroupBySeriesPresentationUniqueKey)
         {
             return false;

Jellyfin.Server.Implementations/Item/ItemPersistenceService.cs

@@ -65,8 +65,13 @@ public class ItemPersistenceService : IItemPersistenceService
             descendantIds.Add(id);
         }
 
+        // Use WhereOneOrMany instead of a raw HashSet.Contains so large id sets are bound as a
+        // single parameter (json_each) rather than one SQL variable per id, which would otherwise
+        // overflow SQLite's variable limit when deleting many items at once (e.g. migrations).
+        var ownerIds = descendantIds.ToArray();
         var extraIds = context.BaseItems
-            .Where(e => e.OwnerId.HasValue && descendantIds.Contains(e.OwnerId.Value))
+            .Where(e => e.OwnerId.HasValue)
+            .WhereOneOrMany(ownerIds, e => e.OwnerId!.Value)
             .Select(e => e.Id)
             .ToArray();
 

Jellyfin.Server.Implementations/Item/OrderMapper.cs

@@ -34,7 +34,14 @@ public static class OrderMapper
             (ItemSortBy.AirTime, _) => e => e.SortName,
             (ItemSortBy.Runtime, _) => e => e.RunTimeTicks,
             (ItemSortBy.Random, _) => e => EF.Functions.Random(),
-            (ItemSortBy.DatePlayed, _) => e => e.UserData!.Where(f => f.UserId.Equals(query.User!.Id)).OrderBy(f => f.CustomDataKey).FirstOrDefault()!.LastPlayedDate,
+            (ItemSortBy.DatePlayed, not null) => e =>
+                jellyfinDbContext.UserData
+                    .Where(w => w.UserId == query.User.Id && (w.ItemId == e.Id || w.Item!.PrimaryVersionId == e.Id))
+                    .Max(f => f.LastPlayedDate),
+            (ItemSortBy.DatePlayed, null) => e =>
+                jellyfinDbContext.UserData
+                    .Where(w => w.ItemId == e.Id || w.Item!.PrimaryVersionId == e.Id)
+                    .Max(f => f.LastPlayedDate),
             (ItemSortBy.PlayCount, _) => e => e.UserData!.Where(f => f.UserId.Equals(query.User!.Id)).OrderBy(f => f.CustomDataKey).FirstOrDefault()!.PlayCount,
             (ItemSortBy.IsFavoriteOrLiked, _) => e => e.UserData!.Where(f => f.UserId.Equals(query.User!.Id)).OrderBy(f => f.CustomDataKey).Select(f => (bool?)f.IsFavorite).FirstOrDefault() ?? false,
             (ItemSortBy.IsFolder, _) => e => e.IsFolder,

Jellyfin.Server.Implementations/Users/UserManager.cs

@@ -170,7 +170,7 @@ namespace Jellyfin.Server.Implementations.Users
         {
             ThrowIfInvalidUsername(newName);
 
-            if (oldName.Equals(newName, StringComparison.OrdinalIgnoreCase))
+            if (oldName.Equals(newName, StringComparison.Ordinal))
             {
                 throw new ArgumentException("The new and old names must be different.");
             }

Jellyfin.Server/Migrations/JellyfinMigrationService.cs

@@ -215,8 +215,11 @@ internal class JellyfinMigrationService
                 logger.LogInformation("There are {Pending} migrations for stage {Stage}.", pendingCodeMigrations.Length, stage);
                 migrations = pendingMigrations.OrderBy(e => e.Key).ToArray();
 
+                var migrationIndex = 0;
                 foreach (var item in migrations)
                 {
+                    // Surface generic "Running migration X of Y" progress in the always-visible startup UI header.
+                    SetupServer.ReportActivity(StartupActivity.Migration(++migrationIndex, migrations.Length));
                     var migrationLogger = logger.With(_loggerFactory.CreateLogger(item.Migration.GetType().Name)).BeginGroup($"{item.Key}");
                     try
                     {

Jellyfin.Server/Migrations/Routines/20250420140000_MigrateAuthenticationDb.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.IO;
 using Emby.Server.Implementations.Data;
 using Jellyfin.Database.Implementations;
@@ -79,9 +80,9 @@ namespace Jellyfin.Server.Migrations.Routines
                 foreach (var row in authenticatedDevices)
                 {
                     var dateCreatedStr = row.GetString(9);
-                    _ = DateTime.TryParse(dateCreatedStr, out var dateCreated);
+                    _ = DateTime.TryParse(dateCreatedStr, CultureInfo.InvariantCulture, out var dateCreated);
                     var dateLastActivityStr = row.GetString(10);
-                    _ = DateTime.TryParse(dateLastActivityStr, out var dateLastActivity);
+                    _ = DateTime.TryParse(dateLastActivityStr, CultureInfo.InvariantCulture, out var dateLastActivity);
 
                     if (row.IsDBNull(6))
                     {

Jellyfin.Server/Migrations/Routines/20260113230000_CleanupOrphanedExtras.cs

@@ -76,25 +76,36 @@ public class CleanupOrphanedExtras : IAsyncMigrationRoutine
 
             _logger.LogInformation("Found {Count} orphaned extras to remove", orphanedItemIds.Count);
 
-            // Batch-resolve items for metadata path cleanup, then delete all at once
-            var itemsToDelete = new List<BaseItem>();
-            foreach (var itemId in orphanedItemIds)
+            // Resolve items for metadata path cleanup, then delete in batches so we never issue one
+            // massive delete transaction and progress stays visible on large libraries.
+            _logger.LogInformation("Deleting {Count} orphaned extras...", orphanedItemIds.Count);
+            const int deleteBatchSize = 500;
+            var deletedSoFar = 0;
+            for (var offset = 0; offset < orphanedItemIds.Count; offset += deleteBatchSize)
             {
-                itemsToDelete.Add(BaseItemMapper.DeserializeBaseItem(
-                    new Database.Implementations.Entities.BaseItemEntity()
-                    {
-                        Id = itemId.Id,
-                        Path = itemId.Path,
-                        Type = itemId.Type
-                    },
-                    _logger,
-                    null,
-                    true)!);
+                cancellationToken.ThrowIfCancellationRequested();
+
+                var batch = orphanedItemIds.GetRange(offset, Math.Min(deleteBatchSize, orphanedItemIds.Count - offset));
+                var itemsToDelete = batch
+                    .Select(itemId => BaseItemMapper.DeserializeBaseItem(
+                        new Database.Implementations.Entities.BaseItemEntity()
+                        {
+                            Id = itemId.Id,
+                            Path = itemId.Path,
+                            Type = itemId.Type
+                        },
+                        _logger,
+                        null,
+                        true)!)
+                    .ToList();
+
+                _libraryManager.DeleteItemsUnsafeFast(itemsToDelete);
+
+                deletedSoFar += batch.Count;
+                _logger.LogInformation("Deleting orphaned extras: {Deleted}/{Total}", deletedSoFar, orphanedItemIds.Count);
             }
 
-            _libraryManager.DeleteItemsUnsafeFast(itemsToDelete);
-
-            _logger.LogInformation("Successfully removed {Count} orphaned extras", itemsToDelete.Count);
+            _logger.LogInformation("Successfully removed {Count} orphaned extras", orphanedItemIds.Count);
         }
     }
 }

Jellyfin.Server/Migrations/Routines/20260115120000_FixIncorrectOwnerIdRelationships.cs

@@ -136,19 +136,38 @@ public class FixIncorrectOwnerIdRelationships : IAsyncMigrationRoutine
 
         if (allIdsToDelete.Count > 0)
         {
-            // Batch-resolve items for metadata path cleanup, then delete all at once
-            var itemsToDelete = allIdsToDelete
-                .Select(id => _libraryManager.GetItemById(id))
-                .Where(item => item is not null)
-                .ToList();
-            _libraryManager.DeleteItemsUnsafeFast(itemsToDelete!);
+            _logger.LogInformation("Deleting {Count} duplicate database entries...", allIdsToDelete.Count);
 
-            // Fall back to direct DB deletion for any items that couldn't be resolved via LibraryManager
-            var deletedIds = itemsToDelete.Select(i => i!.Id).ToHashSet();
-            var unresolvedIds = allIdsToDelete.Where(id => !deletedIds.Contains(id)).ToList();
-            if (unresolvedIds.Count > 0)
+            // Delete in batches so progress is visible (item resolution and deletion can take a
+            // long time on large libraries) and so we never issue one massive delete transaction.
+            const int deleteBatchSize = 500;
+            var deletedSoFar = 0;
+            for (var offset = 0; offset < allIdsToDelete.Count; offset += deleteBatchSize)
             {
-                _persistenceService.DeleteItem(unresolvedIds);
+                cancellationToken.ThrowIfCancellationRequested();
+
+                var batchIds = allIdsToDelete.GetRange(offset, Math.Min(deleteBatchSize, allIdsToDelete.Count - offset));
+
+                // Resolve items for metadata path cleanup, then delete this batch
+                var itemsToDelete = batchIds
+                    .Select(id => _libraryManager.GetItemById(id))
+                    .Where(item => item is not null)
+                    .ToList();
+                if (itemsToDelete.Count > 0)
+                {
+                    _libraryManager.DeleteItemsUnsafeFast(itemsToDelete!);
+                }
+
+                // Fall back to direct DB deletion for any items that couldn't be resolved via LibraryManager
+                var deletedIds = itemsToDelete.Select(i => i!.Id).ToHashSet();
+                var unresolvedIds = batchIds.Where(id => !deletedIds.Contains(id)).ToList();
+                if (unresolvedIds.Count > 0)
+                {
+                    _persistenceService.DeleteItem(unresolvedIds);
+                }
+
+                deletedSoFar += batchIds.Count;
+                _logger.LogInformation("Deleting duplicates: {Deleted}/{Total} items", deletedSoFar, allIdsToDelete.Count);
             }
         }
 

Jellyfin.Server/Migrations/Routines/20260508120000_MergeDuplicateMusicArtists.cs

@@ -182,23 +182,35 @@ public class MergeDuplicateMusicArtists : IAsyncMigrationRoutine
             // Resolve via LibraryManager so DeleteItemsUnsafeFast can also remove the
             // %MetadataPath%/artists/<Name> directories that the duplicate stubs left behind.
             // Fall back to the persistence service for any items the LibraryManager can't resolve.
-            var itemsToDelete = idsToDelete
-                .Select(id => _libraryManager.GetItemById(id))
-                .Where(item => item is not null)
-                .ToList();
-            if (itemsToDelete.Count > 0)
+            // Delete in batches so we never issue one massive delete transaction and progress stays visible.
+            _logger.LogInformation("Deleting {Count} duplicate MusicArtist records...", idsToDelete.Count);
+            const int deleteBatchSize = 500;
+            var deletedSoFar = 0;
+            for (var offset = 0; offset < idsToDelete.Count; offset += deleteBatchSize)
             {
-                _libraryManager.DeleteItemsUnsafeFast(itemsToDelete!);
-            }
+                cancellationToken.ThrowIfCancellationRequested();
 
-            var deletedIds = itemsToDelete.Select(i => i!.Id).ToHashSet();
-            var unresolvedIds = idsToDelete.Where(id => !deletedIds.Contains(id)).ToList();
-            if (unresolvedIds.Count > 0)
-            {
-                _persistenceService.DeleteItem(unresolvedIds);
-            }
+                var batchIds = idsToDelete.GetRange(offset, Math.Min(deleteBatchSize, idsToDelete.Count - offset));
 
-            _logger.LogInformation("Removed {Count} duplicate MusicArtist records.", idsToDelete.Count);
+                var itemsToDelete = batchIds
+                    .Select(id => _libraryManager.GetItemById(id))
+                    .Where(item => item is not null)
+                    .ToList();
+                if (itemsToDelete.Count > 0)
+                {
+                    _libraryManager.DeleteItemsUnsafeFast(itemsToDelete!);
+                }
+
+                var deletedIds = itemsToDelete.Select(i => i!.Id).ToHashSet();
+                var unresolvedIds = batchIds.Where(id => !deletedIds.Contains(id)).ToList();
+                if (unresolvedIds.Count > 0)
+                {
+                    _persistenceService.DeleteItem(unresolvedIds);
+                }
+
+                deletedSoFar += batchIds.Count;
+                _logger.LogInformation("Deleting duplicate MusicArtist records: {Deleted}/{Total}", deletedSoFar, idsToDelete.Count);
+            }
         }
     }
 }

Jellyfin.Server/Migrations/Routines/20260508130000_MergeDuplicatePeople.cs

@@ -184,23 +184,35 @@ public class MergeDuplicatePeople : IAsyncMigrationRoutine
 
         // Resolve via LibraryManager so DeleteItemsUnsafeFast can also remove the
         // %MetadataPath%/People/<Letter>/<Name> directories the duplicate stubs left behind.
-        var itemsToDelete = idsToDelete
-            .Select(id => _libraryManager.GetItemById(id))
-            .Where(item => item is not null)
-            .ToList();
-        if (itemsToDelete.Count > 0)
+        // Delete in batches so we never issue one massive delete transaction and progress stays visible.
+        _logger.LogInformation("Deleting {Count} duplicate Person BaseItems...", idsToDelete.Count);
+        const int deleteBatchSize = 500;
+        var deletedSoFar = 0;
+        for (var offset = 0; offset < idsToDelete.Count; offset += deleteBatchSize)
         {
-            _libraryManager.DeleteItemsUnsafeFast(itemsToDelete!);
-        }
+            cancellationToken.ThrowIfCancellationRequested();
 
-        var deletedIds = itemsToDelete.Select(i => i!.Id).ToHashSet();
-        var unresolvedIds = idsToDelete.Where(id => !deletedIds.Contains(id)).ToList();
-        if (unresolvedIds.Count > 0)
-        {
-            _persistenceService.DeleteItem(unresolvedIds);
-        }
+            var batchIds = idsToDelete.GetRange(offset, Math.Min(deleteBatchSize, idsToDelete.Count - offset));
 
-        _logger.LogInformation("Removed {Count} duplicate Person BaseItems.", idsToDelete.Count);
+            var itemsToDelete = batchIds
+                .Select(id => _libraryManager.GetItemById(id))
+                .Where(item => item is not null)
+                .ToList();
+            if (itemsToDelete.Count > 0)
+            {
+                _libraryManager.DeleteItemsUnsafeFast(itemsToDelete!);
+            }
+
+            var deletedIds = itemsToDelete.Select(i => i!.Id).ToHashSet();
+            var unresolvedIds = batchIds.Where(id => !deletedIds.Contains(id)).ToList();
+            if (unresolvedIds.Count > 0)
+            {
+                _persistenceService.DeleteItem(unresolvedIds);
+            }
+
+            deletedSoFar += batchIds.Count;
+            _logger.LogInformation("Deleting duplicate Person BaseItems: {Deleted}/{Total}", deletedSoFar, idsToDelete.Count);
+        }
     }
 
     private async Task MergePeoplesRowsAsync(JellyfinDbContext context, CancellationToken cancellationToken)

Jellyfin.Server/Program.cs

@@ -133,10 +133,12 @@ namespace Jellyfin.Server
                 }
             }
 
+            SetupServer.ReportActivity(StartupActivity.CheckingStorage);
             StorageHelper.TestCommonPathsForStorageCapacity(appPaths, StartupLogger.Logger.With(_loggerFactory.CreateLogger<Startup>()).BeginGroup($"Storage Check"));
 
             StartupHelpers.PerformStaticInitialization();
 
+            SetupServer.ReportActivity(StartupActivity.Initializing);
             await ApplyStartupMigrationAsync(appPaths, startupConfig, options).ConfigureAwait(false);
 
             do
@@ -195,6 +197,7 @@ namespace Jellyfin.Server
 
                 if (!string.IsNullOrWhiteSpace(_restoreFromBackup))
                 {
+                    SetupServer.ReportActivity(StartupActivity.RestoringBackup);
                     await appHost.ServiceProvider.GetService<IBackupService>()!.RestoreBackupAsync(_restoreFromBackup).ConfigureAwait(false);
                     _restoreFromBackup = null;
                     _restartOnShutdown = true;
@@ -202,9 +205,13 @@ namespace Jellyfin.Server
                 }
 
                 var jellyfinMigrationService = ActivatorUtilities.CreateInstance<JellyfinMigrationService>(appHost.ServiceProvider);
+                SetupServer.ReportActivity(StartupActivity.PreparingMigrations);
                 await jellyfinMigrationService.PrepareSystemForMigration(_logger).ConfigureAwait(false);
+                // "Preparing migrations" carries through the DB read; per-migration progress is reported
+                // as "Running migration X of Y" from inside the step once the pending set is known.
                 await jellyfinMigrationService.MigrateStepAsync(JellyfinMigrationStageTypes.CoreInitialisation, appHost.ServiceProvider).ConfigureAwait(false);
 
+                SetupServer.ReportActivity(StartupActivity.InitializingServices);
                 await appHost.InitializeServices(startupConfig).ConfigureAwait(false);
                 _appHost = appHost;
 

Jellyfin.Server/ServerSetupApp/SetupServer.cs

@@ -14,7 +14,6 @@ using Jellyfin.Server.Extensions;
 using MediaBrowser.Common.Configuration;
 using MediaBrowser.Common.Net;
 using MediaBrowser.Controller;
-using MediaBrowser.Model.IO;
 using MediaBrowser.Model.System;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
@@ -25,9 +24,6 @@ using Microsoft.Extensions.Diagnostics.HealthChecks;
 using Microsoft.Extensions.Hosting;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Primitives;
-using Morestachio;
-using Morestachio.Framework.IO.SingleStream;
-using Morestachio.Rendering;
 using Serilog;
 using ILogger = Microsoft.Extensions.Logging.ILogger;
 
@@ -44,7 +40,8 @@ public sealed class SetupServer : IDisposable
     private readonly ILoggerFactory _loggerFactory;
     private readonly IConfiguration _startupConfiguration;
     private readonly ServerConfigurationManager _configurationManager;
-    private IRenderer? _startupUiRenderer;
+    private static volatile string _currentActivity = StartupActivity.Starting;
+    private StartupUiRenderer? _startupUiRenderer;
     private IHost? _startupServer;
     private bool _disposed;
     private bool _isUnhealthy;
@@ -76,6 +73,12 @@ public sealed class SetupServer : IDisposable
 
     internal static ConcurrentQueue<StartupLogTopic>? LogQueue { get; set; } = new();
 
+    /// <summary>
+    /// Gets a generic, non-identifying summary of what startup is currently doing. This is shown in the
+    /// always-visible header of the startup UI to unauthenticated clients, so it never contains server specific details.
+    /// </summary>
+    internal static string CurrentActivity => _currentActivity;
+
     /// <summary>
     /// Gets a value indicating whether Startup server is currently running.
     /// </summary>
@@ -87,64 +90,9 @@ public sealed class SetupServer : IDisposable
     /// <returns>A Task.</returns>
     public async Task RunAsync()
     {
-        var fileTemplate = await File.ReadAllTextAsync(Path.Combine(AppContext.BaseDirectory, "ServerSetupApp", "index.mstemplate.html")).ConfigureAwait(false);
-        _startupUiRenderer = (await ParserOptionsBuilder.New()
-            .WithTemplate(fileTemplate)
-            .WithFormatter(
-            (Version version, int arg) =>
-            {
-                // version type does not for some stupid reason implement IFormattable which morestachio relies on for ToString support therefor we need to do it manually.
-                return version.ToString(arg);
-            },
-            "ToString")
-            .WithFormatter(
-                (StartupLogTopic logEntry, IEnumerable<StartupLogTopic> children) =>
-                {
-                    if (children.Any())
-                    {
-                        var maxLevel = logEntry.LogLevel;
-                        var stack = new Stack<StartupLogTopic>(children);
-
-                        while (maxLevel != LogLevel.Error && stack.Count > 0 && (logEntry = stack.Pop()) is not null) // error is the highest inherted error level.
-                        {
-                            maxLevel = maxLevel < logEntry.LogLevel ? logEntry.LogLevel : maxLevel;
-                            foreach (var child in logEntry.Children)
-                            {
-                                stack.Push(child);
-                            }
-                        }
-
-                        return maxLevel;
-                    }
-
-                    return logEntry.LogLevel;
-                },
-                "FormatLogLevel")
-            .WithFormatter(
-                (LogLevel logLevel) =>
-                {
-                    switch (logLevel)
-                    {
-                        case LogLevel.Trace:
-                        case LogLevel.Debug:
-                        case LogLevel.None:
-                            return "success";
-                        case LogLevel.Information:
-                            return "info";
-                        case LogLevel.Warning:
-                            return "warn";
-                        case LogLevel.Error:
-                            return "danger";
-                        case LogLevel.Critical:
-                            return "danger-strong";
-                    }
-
-                    return string.Empty;
-                },
-                "ToString")
-            .BuildAndParseAsync()
-            .ConfigureAwait(false))
-            .CreateCompiledRenderer();
+        ReportActivity(StartupActivity.Starting);
+        _startupUiRenderer = await StartupUiRenderer.CreateAsync(
+            Path.Combine(AppContext.BaseDirectory, "ServerSetupApp", "index.mstemplate.html")).ConfigureAwait(false);
 
         ThrowIfDisposed();
         var retryAfterValue = TimeSpan.FromSeconds(5);
@@ -257,13 +205,14 @@ public sealed class SetupServer : IDisposable
                                             new Dictionary<string, object>()
                                             {
                                                 { "isInReportingMode", _isUnhealthy },
+                                                { "currentActivity", CurrentActivity },
                                                 { "retryValue", retryAfterValue },
                                                 { "version", version },
                                                 { "logs", startupLogEntries },
                                                 { "networkManagerReady", networkManager is not null },
                                                 { "localNetworkRequest", networkManager is not null && context.Connection.RemoteIpAddress is not null && networkManager.IsInLocalNetwork(context.Connection.RemoteIpAddress) }
                                             },
-                                            new ByteCounterStream(context.Response.BodyWriter.AsStream(), IODefaults.FileStreamBufferSize, true, _startupUiRenderer.ParserOptions))
+                                            context.Response.BodyWriter.AsStream())
                                             .ConfigureAwait(false);
                                     });
                                 });
@@ -309,6 +258,16 @@ public sealed class SetupServer : IDisposable
         ObjectDisposedException.ThrowIf(_disposed, this);
     }
 
+    /// <summary>
+    /// Reports the current startup activity shown to all clients in the startup UI header.
+    /// Only pass generic, non-identifying text from <see cref="StartupActivity"/>.
+    /// </summary>
+    /// <param name="activity">A generic description such as <see cref="StartupActivity.PreparingMigrations"/>.</param>
+    internal static void ReportActivity(string activity)
+    {
+        _currentActivity = activity;
+    }
+
     internal void SoftStop()
     {
         _isUnhealthy = true;

Jellyfin.Server/ServerSetupApp/StartupActivity.cs

@@ -0,0 +1,41 @@
+using System.Globalization;
+
+namespace Jellyfin.Server.ServerSetupApp;
+
+/// <summary>
+/// A curated vocabulary of generic, non-identifying descriptions of what the server is doing during startup.
+/// These are shown in the always-visible header of the startup UI to <b>unauthenticated</b> clients, so every
+/// value must stay generic and must never contain server specific details (paths, names, plugin or migration ids, counts of items, etc.).
+/// </summary>
+public static class StartupActivity
+{
+    /// <summary>The default state before any work has been reported.</summary>
+    public const string Starting = "Starting up";
+
+    /// <summary>Validating that the configured storage locations are usable.</summary>
+    public const string CheckingStorage = "Checking storage";
+
+    /// <summary>Bringing up the migration subsystem and running early startup checks.</summary>
+    public const string Initializing = "Initializing server";
+
+    /// <summary>Preparing the system for migrations (e.g. taking safety backups).</summary>
+    public const string PreparingMigrations = "Preparing migrations";
+
+    /// <summary>Restoring from a backup.</summary>
+    public const string RestoringBackup = "Restoring backup";
+
+    /// <summary>Bringing up core services and plugins.</summary>
+    public const string InitializingServices = "Initializing services";
+
+    /// <summary>Running the final startup tasks.</summary>
+    public const string FinishingStartup = "Finishing startup";
+
+    /// <summary>
+    /// Builds a generic "Running migration X of Y" description. Only the numeric position and total are exposed.
+    /// </summary>
+    /// <param name="current">The 1-based index of the migration currently running.</param>
+    /// <param name="total">The total number of migrations in this batch.</param>
+    /// <returns>A generic progress description.</returns>
+    public static string Migration(int current, int total)
+        => string.Format(CultureInfo.InvariantCulture, "Running migration {0} of {1}", current, total);
+}

Jellyfin.Server/ServerSetupApp/StartupUiRenderer.cs

@@ -0,0 +1,109 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using MediaBrowser.Model.IO;
+using Microsoft.Extensions.Logging;
+using Morestachio;
+using Morestachio.Framework.IO.SingleStream;
+using Morestachio.Rendering;
+
+namespace Jellyfin.Server.ServerSetupApp;
+
+/// <summary>
+/// Compiles and renders the startup UI Morestachio template.
+/// Shared by the live <see cref="SetupServer"/> and the standalone startup UI preview tool so both
+/// exercise the exact same template and formatters.
+/// </summary>
+public sealed class StartupUiRenderer
+{
+    private readonly IRenderer _renderer;
+
+    private StartupUiRenderer(IRenderer renderer)
+    {
+        _renderer = renderer;
+    }
+
+    /// <summary>
+    /// Compiles the startup UI template located at <paramref name="templatePath"/>.
+    /// </summary>
+    /// <param name="templatePath">The full path to the <c>index.mstemplate.html</c> template.</param>
+    /// <returns>A ready to use <see cref="StartupUiRenderer"/>.</returns>
+    public static async Task<StartupUiRenderer> CreateAsync(string templatePath)
+    {
+        var fileTemplate = await File.ReadAllTextAsync(templatePath).ConfigureAwait(false);
+        var renderer = (await ParserOptionsBuilder.New()
+            .WithTemplate(fileTemplate)
+            .WithFormatter(
+            (Version version, int arg) =>
+            {
+                // version type does not for some stupid reason implement IFormattable which morestachio relies on for ToString support therefor we need to do it manually.
+                return version.ToString(arg);
+            },
+            "ToString")
+            .WithFormatter(
+                (StartupLogTopic logEntry, IEnumerable<StartupLogTopic> children) =>
+                {
+                    if (children.Any())
+                    {
+                        var maxLevel = logEntry.LogLevel;
+                        var stack = new Stack<StartupLogTopic>(children);
+
+                        while (maxLevel != LogLevel.Error && stack.Count > 0 && (logEntry = stack.Pop()) is not null) // error is the highest inherted error level.
+                        {
+                            maxLevel = maxLevel < logEntry.LogLevel ? logEntry.LogLevel : maxLevel;
+                            foreach (var child in logEntry.Children)
+                            {
+                                stack.Push(child);
+                            }
+                        }
+
+                        return maxLevel;
+                    }
+
+                    return logEntry.LogLevel;
+                },
+                "FormatLogLevel")
+            .WithFormatter(
+                (LogLevel logLevel) =>
+                {
+                    switch (logLevel)
+                    {
+                        case LogLevel.Trace:
+                        case LogLevel.Debug:
+                        case LogLevel.None:
+                            return "success";
+                        case LogLevel.Information:
+                            return "info";
+                        case LogLevel.Warning:
+                            return "warn";
+                        case LogLevel.Error:
+                            return "danger";
+                        case LogLevel.Critical:
+                            return "danger-strong";
+                    }
+
+                    return string.Empty;
+                },
+                "ToString")
+            .BuildAndParseAsync()
+            .ConfigureAwait(false))
+            .CreateCompiledRenderer();
+
+        return new StartupUiRenderer(renderer);
+    }
+
+    /// <summary>
+    /// Renders the template with the provided model into the target stream.
+    /// </summary>
+    /// <param name="model">The values made available to the template.</param>
+    /// <param name="output">The stream the rendered HTML is written to.</param>
+    /// <returns>A Task.</returns>
+    public Task RenderAsync(IDictionary<string, object> model, Stream output)
+    {
+        return _renderer.RenderAsync(
+            model,
+            new ByteCounterStream(output, IODefaults.FileStreamBufferSize, true, _renderer.ParserOptions));
+    }
+}

MediaBrowser.Controller/Entities/BaseItem.cs

@@ -87,6 +87,8 @@ namespace MediaBrowser.Controller.Entities
             Model.Entities.ExtraType.Short
         };
 
+        private static readonly char[] VersionDelimiters = ['-', '_', '.'];
+
         private string _sortName;
 
         private string _forcedSortName;
@@ -1099,8 +1101,9 @@ namespace MediaBrowser.Controller.Entities
                 }
             }
 
-            var list = GetAllItemsForMediaSources();
-            var result = list.Select(i => GetVersionInfo(enablePathSubstitution, i.Item, i.MediaSourceType)).ToList();
+            var list = GetAllItemsForMediaSources().ToList();
+            var commonPrefix = GetCommonNamePrefix(list);
+            var result = list.Select(i => GetVersionInfo(enablePathSubstitution, i.Item, i.MediaSourceType, commonPrefix)).ToList();
 
             if (IsActiveRecording())
             {
@@ -1110,17 +1113,15 @@ namespace MediaBrowser.Controller.Entities
                 }
             }
 
-            return result.OrderBy(i =>
-            {
-                if (i.VideoType == VideoType.VideoFile)
-                {
-                    return 0;
-                }
+            // The source belonging to the item being queried sorts first so it is the default the client plays.
+            var selfId = Id.ToString("N", CultureInfo.InvariantCulture);
 
-                return 1;
-            }).ThenBy(i => i.Video3DFormat.HasValue ? 1 : 0)
-            .ThenByDescending(i => i, new MediaSourceWidthComparator())
-            .ToArray();
+            return result
+                .OrderByDescending(i => string.Equals(i.Id, selfId, StringComparison.OrdinalIgnoreCase))
+                .ThenBy(i => i.VideoType == VideoType.VideoFile ? 0 : 1)
+                .ThenBy(i => i.Video3DFormat.HasValue ? 1 : 0)
+                .ThenByDescending(i => i, new MediaSourceWidthComparator())
+                .ToArray();
         }
 
         protected virtual IEnumerable<(BaseItem Item, MediaSourceType MediaSourceType)> GetAllItemsForMediaSources()
@@ -1128,7 +1129,7 @@ namespace MediaBrowser.Controller.Entities
             return Enumerable.Empty<(BaseItem, MediaSourceType)>();
         }
 
-        private MediaSourceInfo GetVersionInfo(bool enablePathSubstitution, BaseItem item, MediaSourceType type)
+        private MediaSourceInfo GetVersionInfo(bool enablePathSubstitution, BaseItem item, MediaSourceType type, string commonPrefix = null)
         {
             ArgumentNullException.ThrowIfNull(item);
 
@@ -1141,7 +1142,7 @@ namespace MediaBrowser.Controller.Entities
                 Protocol = protocol ?? MediaProtocol.File,
                 MediaStreams = MediaSourceManager.GetMediaStreams(item.Id),
                 MediaAttachments = MediaSourceManager.GetMediaAttachments(item.Id),
-                Name = GetMediaSourceName(item),
+                Name = GetMediaSourceName(item, commonPrefix),
                 Path = enablePathSubstitution ? GetMappedPath(item, itemPath, protocol) : itemPath,
                 RunTimeTicks = item.RunTimeTicks,
                 Container = item.Container,
@@ -1220,7 +1221,7 @@ namespace MediaBrowser.Controller.Entities
             return info;
         }
 
-        internal string GetMediaSourceName(BaseItem item)
+        internal string GetMediaSourceName(BaseItem item, string commonPrefix = null)
         {
             var terms = new List<string>();
 
@@ -1228,12 +1229,31 @@ namespace MediaBrowser.Controller.Entities
             if (item.IsFileProtocol && !string.IsNullOrEmpty(path))
             {
                 var displayName = System.IO.Path.GetFileNameWithoutExtension(path);
-                if (HasLocalAlternateVersions)
+
+                // Prefer the suffix that differs from the other versions: strip the prefix shared by
+                // all sibling files. This works regardless of folder layout, so it also labels episode
+                // versions that share a season folder (e.g. "Greyscale" instead of the full
+                // "Show - S01E02 - Title - Greyscale"). The prefix is already retreated to a delimiter
+                // boundary (see GetCommonVersionPrefix).
+                if (!string.IsNullOrEmpty(commonPrefix)
+                    && displayName.Length > commonPrefix.Length
+                    && displayName.StartsWith(commonPrefix, StringComparison.OrdinalIgnoreCase))
+                {
+                    var name = displayName.AsSpan(commonPrefix.Length).TrimStart([' ', .. VersionDelimiters]);
+                    if (!name.IsWhiteSpace())
+                    {
+                        terms.Add(name.ToString());
+                    }
+                }
+
+                // Fall back to the containing folder name (the common layout for movie versions, and
+                // the path taken when no common prefix could be derived).
+                if (terms.Count == 0 && HasLocalAlternateVersions)
                 {
                     var containingFolderName = System.IO.Path.GetFileName(ContainingFolderPath);
                     if (displayName.Length > containingFolderName.Length && displayName.StartsWith(containingFolderName, StringComparison.OrdinalIgnoreCase))
                     {
-                        var name = displayName.AsSpan(containingFolderName.Length).TrimStart([' ', '-']);
+                        var name = displayName.AsSpan(containingFolderName.Length).TrimStart([' ', .. VersionDelimiters]);
                         if (!name.IsWhiteSpace())
                         {
                             terms.Add(name.ToString());
@@ -1290,6 +1310,98 @@ namespace MediaBrowser.Controller.Entities
             return string.Join('/', terms);
         }
 
+        /// <summary>
+        /// Derives the prefix shared by the supplied media source items' file names, used to strip the
+        /// common part and surface a short version label per source. Returns null when there are fewer
+        /// than two file-based sources, since there is nothing to differentiate.
+        /// </summary>
+        /// <param name="items">The media source items.</param>
+        /// <returns>The shared prefix, or null when no useful prefix exists.</returns>
+        private static string GetCommonNamePrefix(IReadOnlyList<(BaseItem Item, MediaSourceType MediaSourceType)> items)
+        {
+            var fileNames = new List<string>();
+            foreach (var (item, _) in items)
+            {
+                if (item.IsFileProtocol && !string.IsNullOrEmpty(item.Path))
+                {
+                    fileNames.Add(System.IO.Path.GetFileNameWithoutExtension(item.Path));
+                }
+            }
+
+            if (fileNames.Count < 2)
+            {
+                return null;
+            }
+
+            var prefix = GetCommonVersionPrefix(fileNames);
+            return string.IsNullOrEmpty(prefix) ? null : prefix;
+        }
+
+        /// <summary>
+        /// Computes the case-insensitive longest common prefix of the supplied version file names,
+        /// retreated to the last delimiter boundary. Retreating keeps the differing suffix intact:
+        /// it avoids slicing through a word every version shares (e.g. "Grey" in "Greyscale" and
+        /// "Greyish") while still trimming the common part when every version is suffixed (e.g.
+        /// "- Greyscale" / "- Colorized"). It prefers a structural delimiter ('-', '_', '.') so a
+        /// token shared by the descriptors but separated only by spaces (e.g. a common "2160p ") is
+        /// kept in the label, falling back to a space only when no structural delimiter is shared. The
+        /// separators mirror the version delimiters recognised by the naming layer (Emby.Naming
+        /// VideoFlagDelimiters).
+        /// </summary>
+        /// <param name="fileNames">The version file names without extension; must contain at least one entry.</param>
+        /// <returns>The shared prefix retreated to a separator boundary, or an empty string when none is shared.</returns>
+        internal static string GetCommonVersionPrefix(IReadOnlyList<string> fileNames)
+        {
+            var prefix = fileNames[0];
+            for (var i = 1; i < fileNames.Count && prefix.Length > 0; i++)
+            {
+                var name = fileNames[i];
+                var length = Math.Min(prefix.Length, name.Length);
+                var common = 0;
+                while (common < length && char.ToUpperInvariant(prefix[common]) == char.ToUpperInvariant(name[common]))
+                {
+                    common++;
+                }
+
+                prefix = prefix[..common];
+            }
+
+            // If the common prefix is itself a whole file name then one version is unlabelled (the
+            // base name); the boundary already sits at the end of that name, so don't retreat into it.
+            var prefixIsWholeName = false;
+            for (var i = 0; i < fileNames.Count; i++)
+            {
+                if (fileNames[i].Length == prefix.Length)
+                {
+                    prefixIsWholeName = true;
+                    break;
+                }
+            }
+
+            if (!prefixIsWholeName)
+            {
+                // Retreat to the last structural delimiter ('-', '_', '.').
+                var cut = prefix.Length;
+                while (cut > 0 && Array.IndexOf(VersionDelimiters, prefix[cut - 1]) < 0)
+                {
+                    cut--;
+                }
+
+                if (cut == 0)
+                {
+                    cut = prefix.Length;
+                    while (cut > 0 && prefix[cut - 1] != ' ')
+                    {
+                        cut--;
+                    }
+                }
+
+                prefix = prefix[..cut];
+            }
+
+            return prefix;
+        }
+
         public Task RefreshMetadata(CancellationToken cancellationToken)
         {
             return RefreshMetadata(new MetadataRefreshOptions(new DirectoryService(FileSystem)), cancellationToken);
@@ -2011,12 +2123,23 @@ namespace MediaBrowser.Controller.Entities
             // I think it is okay to do this here.
             // if this is only called when a user is manually forcing something to un-played
             // then it probably is what we want to do...
+            ResetPlayedState(data);
+
+            UserDataManager.SaveUserData(user, this, data, UserDataSaveReason.TogglePlayed, CancellationToken.None);
+        }
+
+        /// <summary>
+        /// Clears the played state on the supplied user data.
+        /// </summary>
+        /// <param name="data">The user data to reset.</param>
+        protected static void ResetPlayedState(UserItemData data)
+        {
+            ArgumentNullException.ThrowIfNull(data);
+
             data.PlayCount = 0;
             data.PlaybackPositionTicks = 0;
             data.LastPlayedDate = null;
             data.Played = false;
-
-            UserDataManager.SaveUserData(user, this, data, UserDataSaveReason.TogglePlayed, CancellationToken.None);
         }
 
         /// <summary>
@@ -2731,6 +2854,15 @@ namespace MediaBrowser.Controller.Entities
             return LibraryManager.Sort(GetExtras(user).Where(e => e.ExtraType == Model.Entities.ExtraType.ThemeVideo), user, orderBy).ToArray();
         }
 
+        /// <summary>
+        /// Gets the ids of the items whose owned extras belong to this item.
+        /// </summary>
+        /// <returns>An array containing the owner ids.</returns>
+        protected virtual Guid[] GetExtraOwnerIds()
+        {
+            return [Id];
+        }
+
         /// <summary>
         /// Get all extras associated with this item, sorted by <see cref="SortName"/>.
         /// </summary>
@@ -2740,7 +2872,7 @@ namespace MediaBrowser.Controller.Entities
         {
             return LibraryManager.GetItemList(new InternalItemsQuery(user)
             {
-                OwnerIds = [Id],
+                OwnerIds = GetExtraOwnerIds(),
                 OrderBy = [(ItemSortBy.SortName, SortOrder.Ascending)]
             });
         }
@@ -2755,7 +2887,7 @@ namespace MediaBrowser.Controller.Entities
         {
             return LibraryManager.GetItemList(new InternalItemsQuery(user)
             {
-                OwnerIds = [Id],
+                OwnerIds = GetExtraOwnerIds(),
                 ExtraTypes = extraTypes.ToArray(),
                 OrderBy = [(ItemSortBy.SortName, SortOrder.Ascending)]
             });

MediaBrowser.Controller/Entities/Folder.cs

@@ -384,6 +384,7 @@ namespace MediaBrowser.Controller.Entities
             cancellationToken.ThrowIfCancellationRequested();
 
             var validChildren = new List<BaseItem>();
+            var accessibleChildren = new List<BaseItem>();
             var validChildrenNeedGeneration = false;
 
             if (IsFileProtocol)
@@ -438,12 +439,19 @@ namespace MediaBrowser.Controller.Entities
                 {
                     if (!IsLibraryFolderAccessible(directoryService, child, allowRemoveRoot))
                     {
+                        // Preserve inaccessible items so they aren't treated as removed.
+                        if (currentChildren.TryGetValue(child.Id, out var childrenToKeep))
+                        {
+                            validChildren.Add(childrenToKeep);
+                        }
+
                         continue;
                     }
 
                     if (currentChildren.TryGetValue(child.Id, out BaseItem currentChild))
                     {
                         validChildren.Add(currentChild);
+                        accessibleChildren.Add(currentChild);
 
                         if (currentChild.UpdateFromResolvedItem(child) > ItemUpdateType.None)
                         {
@@ -480,11 +488,12 @@ namespace MediaBrowser.Controller.Entities
                     child.SetParent(this);
                     newItems.Add(child);
                     validChildren.Add(child);
+                    accessibleChildren.Add(child);
                 }
 
                 // That's all the new and changed ones - now see if any have been removed and need cleanup
                 var itemsRemoved = currentChildren.Values.Except(validChildren).ToList();
-                var shouldRemove = !IsRoot || allowRemoveRoot;
+
                 // If it's an AggregateFolder, don't remove
                 // Collect replaced primaries for deferred deletion (after CreateItems)
                 var replacedPrimaries = new List<(Video OldPrimary, Video NewPrimary)>();
@@ -497,7 +506,7 @@ namespace MediaBrowser.Controller.Entities
                     .Where(p => !string.IsNullOrEmpty(p))
                     .ToHashSet(StringComparer.OrdinalIgnoreCase);
 
-                if (shouldRemove && itemsRemoved.Count > 0)
+                if (itemsRemoved.Count > 0)
                 {
                     foreach (var item in itemsRemoved)
                     {
@@ -703,7 +712,7 @@ namespace MediaBrowser.Controller.Entities
                     validChildrenNeedGeneration = false;
                 }
 
-                await ValidateSubFolders(validChildren.OfType<Folder>().ToList(), directoryService, innerProgress, cancellationToken).ConfigureAwait(false);
+                await ValidateSubFolders(accessibleChildren.OfType<Folder>().ToList(), directoryService, innerProgress, cancellationToken).ConfigureAwait(false);
             }
 
             if (refreshChildMetadata)
@@ -742,7 +751,7 @@ namespace MediaBrowser.Controller.Entities
                         validChildren = Children.ToList();
                     }
 
-                    await RefreshMetadataRecursive(validChildren, refreshOptions, recursive, innerProgress, cancellationToken).ConfigureAwait(false);
+                    await RefreshMetadataRecursive(accessibleChildren, refreshOptions, recursive, innerProgress, cancellationToken).ConfigureAwait(false);
                 }
             }
         }

MediaBrowser.Controller/Entities/UserViewBuilder.cs

@@ -61,6 +61,9 @@ namespace MediaBrowser.Controller.Entities
                 case CollectionType.folders:
                     return GetResult(_libraryManager.GetUserRootFolder().GetChildren(user, true), query);
 
+                case CollectionType.books:
+                    return GetBooks(queryParent, user, query);
+
                 case CollectionType.tvshows:
                     return GetTvView(queryParent, user, query);
 
@@ -190,6 +193,17 @@ namespace MediaBrowser.Controller.Entities
             return _libraryManager.GetItemsResult(query);
         }
 
+        private QueryResult<BaseItem> GetBooks(Folder parent, User user, InternalItemsQuery query)
+        {
+            query.Recursive = true;
+            query.Parent = parent;
+            query.SetUser(user);
+
+            query.IncludeItemTypes = new[] { BaseItemKind.Book, BaseItemKind.AudioBook };
+
+            return _libraryManager.GetItemsResult(query);
+        }
+
         private QueryResult<BaseItem> GetMovieMovies(Folder parent, User user, InternalItemsQuery query)
         {
             query.Recursive = true;

MediaBrowser.Controller/Entities/Video.cs

@@ -34,11 +34,11 @@ namespace MediaBrowser.Controller.Entities
     {
         public Video()
         {
-            AdditionalParts = Array.Empty<string>();
-            LocalAlternateVersions = Array.Empty<string>();
-            SubtitleFiles = Array.Empty<string>();
-            AudioFiles = Array.Empty<string>();
-            LinkedAlternateVersions = Array.Empty<LinkedChild>();
+            AdditionalParts = [];
+            LocalAlternateVersions = [];
+            SubtitleFiles = [];
+            AudioFiles = [];
+            LinkedAlternateVersions = [];
         }
 
         [JsonIgnore]
@@ -254,7 +254,7 @@ namespace MediaBrowser.Controller.Entities
 
         private int GetMediaSourceCount(HashSet<Guid> callstack = null)
         {
-            callstack ??= new();
+            callstack ??= [];
             if (PrimaryVersionId.HasValue)
             {
                 var item = LibraryManager.GetItemById(PrimaryVersionId.Value);
@@ -335,6 +335,102 @@ namespace MediaBrowser.Controller.Entities
             PresentationUniqueKey = CreatePresentationUniqueKey();
         }
 
+        /// <summary>
+        /// Marks the played status of this video and propagates it to its alternate versions.
+        /// </summary>
+        /// <param name="user">The user.</param>
+        /// <param name="datePlayed">The date played.</param>
+        /// <param name="resetPosition">if set to <c>true</c> [reset position].</param>
+        public override void MarkPlayed(User user, DateTime? datePlayed, bool resetPosition)
+        {
+            base.MarkPlayed(user, datePlayed, resetPosition);
+            PropagatePlayedState(user, true, resetPosition);
+        }
+
+        /// <summary>
+        /// Marks this video unplayed and propagates the change to its alternate versions.
+        /// </summary>
+        /// <param name="user">The user.</param>
+        public override void MarkUnplayed(User user)
+        {
+            base.MarkUnplayed(user);
+
+            // MarkUnplayed always clears the position on this video, so reset the versions too.
+            PropagatePlayedState(user, false, true);
+        }
+
+        /// <summary>
+        /// Propagates the played status to every alternate version of this video.
+        /// </summary>
+        /// <param name="user">The user.</param>
+        /// <param name="played">The played status to apply to the alternate versions.</param>
+        /// <param name="resetPosition">When marking played, controls whether each version's resume point
+        /// is also reset (<c>true</c>) or left untouched (<c>false</c>). Ignored when marking unplayed,
+        /// which always fully resets every version.</param>
+        public void PropagatePlayedState(User user, bool played, bool resetPosition = true)
+        {
+            ArgumentNullException.ThrowIfNull(user);
+
+            if (!PrimaryVersionId.HasValue && LinkedAlternateVersions.Length == 0 && !HasLocalAlternateVersions)
+            {
+                return;
+            }
+
+            foreach (var (item, _) in GetAllItemsForMediaSources())
+            {
+                if (item.Id.Equals(Id) || item is not Video)
+                {
+                    continue;
+                }
+
+                if (played)
+                {
+                    var dto = new UpdateUserItemDataDto { Played = true };
+                    if (resetPosition)
+                    {
+                        dto.PlaybackPositionTicks = 0;
+                    }
+
+                    // SaveUserData only writes the fields set on the DTO, so play count and other state are preserved.
+                    UserDataManager.SaveUserData(user, item, dto, UserDataSaveReason.TogglePlayed);
+                }
+                else
+                {
+                    var data = UserDataManager.GetUserData(user, item);
+                    if (data is null)
+                    {
+                        continue;
+                    }
+
+                    ResetPlayedState(data);
+                    UserDataManager.SaveUserData(user, item, data, UserDataSaveReason.TogglePlayed, CancellationToken.None);
+                }
+            }
+        }
+
+        /// <summary>
+        /// Gets this video together with all of its alternate versions (local and linked and, when this
+        /// is itself an alternate, the primary and the primary's other versions), deduplicated.
+        /// </summary>
+        /// <returns>This video and every alternate version of it.</returns>
+        public IReadOnlyList<Video> GetAllVersions()
+        {
+            return GetAllItemsForMediaSources()
+                .Select(i => i.Item)
+                .OfType<Video>()
+                .ToList();
+        }
+
+        /// <summary>
+        /// Gets the alternate version of this video that matches the supplied item id.
+        /// </summary>
+        /// <param name="itemId">The version item id (the playback media source id).</param>
+        /// <returns>The matching version, or <c>null</c> when the id is not a version of this video.</returns>
+        public Video GetAlternateVersion(Guid itemId)
+        {
+            return GetAllVersions().FirstOrDefault(i => i.Id.Equals(itemId));
+        }
+
         public override string CreatePresentationUniqueKey()
         {
             if (PrimaryVersionId.HasValue)
@@ -642,39 +738,58 @@ namespace MediaBrowser.Controller.Entities
             }).FirstOrDefault();
         }
 
+        /// <summary>
+        /// Gets the ids of the items whose owned extras belong to this item.
+        /// Extras are linked to a single version but need tp be surfaced for all versions.
+        /// </summary>
+        /// <returns>An array containing the owner ids.</returns>
+        protected override Guid[] GetExtraOwnerIds()
+        {
+            return GetAllItemsForMediaSources()
+                .Select(i => i.Item.Id)
+                .Distinct()
+                .ToArray();
+        }
+
         protected override IEnumerable<(BaseItem Item, MediaSourceType MediaSourceType)> GetAllItemsForMediaSources()
         {
-            var list = new List<(BaseItem, MediaSourceType)>
-            {
-                (this, MediaSourceType.Default)
-            };
+            var primary = PrimaryVersionId.HasValue
+                ? LibraryManager.GetItemById(PrimaryVersionId.Value) as Video
+                : null;
 
-            list.AddRange(
-                LibraryManager.GetLinkedAlternateVersions(this)
-                    .Select(i => ((BaseItem)i, MediaSourceType.Grouping)));
+            var primaryLinked = primary is null
+                ? []
+                : LibraryManager.GetLinkedAlternateVersions(primary).ToList();
 
-            if (PrimaryVersionId.HasValue)
-            {
-                if (LibraryManager.GetItemById(PrimaryVersionId.Value) is Video primary)
-                {
-                    var existingIds = list.Select(i => i.Item1.Id).ToList();
-                    list.Add((primary, MediaSourceType.Grouping));
-                    list.AddRange(LibraryManager.GetLinkedAlternateVersions(primary).Where(i => !existingIds.Contains(i.Id)).Select(i => ((BaseItem)i, MediaSourceType.Grouping)));
-                }
-            }
+            // Grouping marks user-merged (splittable) sources. The primary is only such a source when
+            // this video is linked onto it; for local (file-based) alternates the primary is just
+            // another default source.
+            var primaryType = primaryLinked.Any(i => i.Id.Equals(Id))
+                ? MediaSourceType.Grouping
+                : MediaSourceType.Default;
 
-            var localAlternates = list
-                .SelectMany(i =>
-                {
-                    return i.Item1 is Video video ? LibraryManager.GetLocalAlternateVersionIds(video) : Enumerable.Empty<Guid>();
-                })
-                .Select(LibraryManager.GetItemById)
-                .Where(i => i is not null)
+            // This video and its linked alternates, when this is itself an alternate, the primary and the primary's linked alternates.
+            var grouped = new[] { ((BaseItem)this, MediaSourceType.Default) }
+                .Concat(LibraryManager.GetLinkedAlternateVersions(this).Select(i => ((BaseItem)i, MediaSourceType.Grouping)))
+                .Concat(primary is null
+                    ? []
+                    : primaryLinked.Select(i => ((BaseItem)i, MediaSourceType.Grouping)).Prepend(((BaseItem)primary, primaryType)))
                 .ToList();
 
-            list.AddRange(localAlternates.Select(i => (i, MediaSourceType.Default)));
+            // The local (file-based) alternate versions of every grouped item.
+            var localAlternates = grouped
+                .Select(i => i.Item1)
+                .OfType<Video>()
+                .SelectMany(LibraryManager.GetLocalAlternateVersionIds)
+                .Select(LibraryManager.GetItemById)
+                .Where(i => i is not null)
+                .Select(i => (i, MediaSourceType.Default));
 
-            return list;
+            // Deduplicate
+            return grouped
+                .Concat(localAlternates)
+                .DistinctBy(i => i.Item1.Id)
+                .ToList();
         }
     }
 }

MediaBrowser.Controller/Library/IUserDataManager.cs

@@ -62,6 +62,24 @@ namespace MediaBrowser.Controller.Library
         /// <returns>A dictionary mapping item IDs to their user data.</returns>
         Dictionary<Guid, UserItemData> GetUserDataBatch(IReadOnlyList<BaseItem> items, User user);
 
+        /// <summary>
+        /// Gets the user data that should drive resume for a multi-version item: the data of the most
+        /// recently played alternate version (including the item itself) that has a resume point.
+        /// </summary>
+        /// <param name="user">The user.</param>
+        /// <param name="item">The item.</param>
+        /// <returns>The resume version's data, or <c>null</c> when the item has no versions or none has a resume point.</returns>
+        VersionResumeData? GetResumeUserData(User user, BaseItem item);
+
+        /// <summary>
+        /// Gets the resume-driving user data for multiple items in a single batch operation.
+        /// See <see cref="GetResumeUserData(User, BaseItem)"/>.
+        /// </summary>
+        /// <param name="items">The items to get resume data for.</param>
+        /// <param name="user">The user.</param>
+        /// <returns>A dictionary mapping item ids to their resume version's data; items without one are omitted.</returns>
+        IReadOnlyDictionary<Guid, VersionResumeData> GetResumeUserDataBatch(IReadOnlyList<BaseItem> items, User user);
+
         /// <summary>
         /// Gets the user data dto.
         /// </summary>
@@ -80,5 +98,13 @@ namespace MediaBrowser.Controller.Library
         /// <param name="reportedPositionTicks">New playstate.</param>
         /// <returns>True if playstate was updated.</returns>
         bool UpdatePlayState(BaseItem item, UserItemData data, long? reportedPositionTicks);
+
+        /// <summary>
+        /// Clears any stored audio and subtitle stream selections for the given user/item pair.
+        /// Used when the user has opted out of remembering selections.
+        /// </summary>
+        /// <param name="user">The user.</param>
+        /// <param name="item">The item.</param>
+        void ResetPlaybackStreamSelections(User user, BaseItem item);
     }
 }

MediaBrowser.Controller/Library/VersionPlaybackSelector.cs

@@ -0,0 +1,59 @@
+using System;
+using System.Collections.Generic;
+using MediaBrowser.Controller.Entities;
+
+namespace MediaBrowser.Controller.Library
+{
+    /// <summary>
+    /// Single definition of "which alternate version was most recently played" shared by the resume tile
+    /// (<see cref="IUserDataManager.GetResumeUserData"/>), the media-source default ordering and Next Up.
+    /// Each call site declares its own eligibility rule so the intentional differences (resumable-only vs.
+    /// resumable-or-completed) are visible in one place instead of being re-implemented divergently.
+    /// The SQL resume query keeps its own translation of the same rule.
+    /// </summary>
+    public static class VersionPlaybackSelector
+    {
+        /// <summary>
+        /// Selects the entry whose user data has the greatest <see cref="UserItemData.LastPlayedDate"/>,
+        /// considering only entries that satisfy <paramref name="isEligible"/>. On an exact tie the first
+        /// encountered entry wins.
+        /// </summary>
+        /// <typeparam name="T">The candidate type (e.g. a version item or a media source).</typeparam>
+        /// <param name="items">The candidates to choose from.</param>
+        /// <param name="dataSelector">Resolves the user data for a candidate, or <c>null</c> when it has none.</param>
+        /// <param name="isEligible">Whether a candidate's user data makes it a valid winner.</param>
+        /// <returns>The most recently played eligible candidate, or <c>default</c> when none qualify.</returns>
+        public static T? SelectMostRecentlyPlayed<T>(
+            IEnumerable<T> items,
+            Func<T, UserItemData?> dataSelector,
+            Func<UserItemData, bool> isEligible)
+        {
+            ArgumentNullException.ThrowIfNull(items);
+            ArgumentNullException.ThrowIfNull(dataSelector);
+            ArgumentNullException.ThrowIfNull(isEligible);
+
+            T? winner = default;
+            var winnerDate = DateTime.MinValue;
+            var hasWinner = false;
+
+            foreach (var item in items)
+            {
+                var data = dataSelector(item);
+                if (data is null || !isEligible(data))
+                {
+                    continue;
+                }
+
+                var date = data.LastPlayedDate ?? DateTime.MinValue;
+                if (!hasWinner || date > winnerDate)
+                {
+                    winner = item;
+                    winnerDate = date;
+                    hasWinner = true;
+                }
+            }
+
+            return winner;
+        }
+    }
+}

MediaBrowser.Controller/Library/VersionResumeData.cs

@@ -0,0 +1,41 @@
+using System;
+using MediaBrowser.Controller.Entities;
+using MediaBrowser.Model.Dto;
+
+namespace MediaBrowser.Controller.Library
+{
+    /// <summary>
+    /// The user data of the most recently played alternate version that should drive the completion state of a multi-version item.
+    /// </summary>
+    /// <param name="VersionId">The id of the version that owns <paramref name="UserData"/>.</param>
+    /// <param name="UserData">The resume version's user data.</param>
+    public record VersionResumeData(Guid VersionId, UserItemData UserData)
+    {
+        /// <summary>
+        /// Merges the most recently played version's completion state into the supplied user data dto.
+        /// Completion (played) propagates to the primary. An in-progress resume position stays on the version
+        /// that owns it, which is surfaced directly (e.g. in resume queries) so that playback always targets
+        /// the correct version rather than resuming the primary at another version's offset. When the movie was
+        /// finished on a different version, the primary's own stale resume position is cleared so it does not
+        /// render as "watched and resumable" at the same time.
+        /// </summary>
+        /// <param name="dto">The user data dto to update.</param>
+        public void ApplyTo(UserItemDataDto dto)
+        {
+            dto.Played = dto.Played || UserData.Played;
+
+            if ((UserData.LastPlayedDate ?? DateTime.MinValue) > (dto.LastPlayedDate ?? DateTime.MinValue))
+            {
+                dto.LastPlayedDate = UserData.LastPlayedDate;
+            }
+
+            // A different version was finished (played, no resume position of its own) and is the most
+            // recently played: the whole movie is watched.
+            if (!VersionId.Equals(dto.ItemId) && UserData.Played && UserData.PlaybackPositionTicks <= 0)
+            {
+                dto.PlaybackPositionTicks = 0;
+                dto.PlayedPercentage = null;
+            }
+        }
+    }
+}

MediaBrowser.LocalMetadata/Images/LocalImageProvider.cs

@@ -84,7 +84,7 @@ namespace MediaBrowser.LocalMetadata.Images
             if (item.SupportsLocalMetadata)
             {
                 // Episode has its own provider
-                if (item is Episode || item is Audio || item is Photo)
+                if (item is Episode || (item is Audio && item is not AudioBook) || item is Photo)
                 {
                     return false;
                 }

MediaBrowser.MediaEncoding/Probing/ProbeResultNormalizer.cs

@@ -254,16 +254,38 @@ namespace MediaBrowser.MediaEncoding.Probing
                 {
                     if (mediaStream.Type == MediaStreamType.Audio && !mediaStream.BitRate.HasValue)
                     {
-                        mediaStream.BitRate = GetEstimatedAudioBitrate(mediaStream.Codec, mediaStream.Channels);
+                        mediaStream.BitRate = GetEstimatedAudioBitrate(mediaStream.Codec, mediaStream.Profile, mediaStream.Channels);
                     }
                 }
 
-                var videoStreamsBitrate = info.MediaStreams.Where(i => i.Type == MediaStreamType.Video).Select(i => i.BitRate ?? 0).Sum();
-                // If ffprobe reported the container bitrate as being the same as the video stream bitrate, then it's wrong
-                if (videoStreamsBitrate == (info.Bitrate ?? 0))
+                // ffprobe frequently omits the per-stream video bitrate (common in MP4/MKV containers).
+                // Estimate the missing video bitrate as the container bitrate minus the combined stream bitrates.
+                var videoStreams = info.MediaStreams.Where(i => i.Type == MediaStreamType.Video).ToList();
+                if (info.Bitrate.HasValue
+                    && videoStreams.Count == 1
+                    && !videoStreams[0].BitRate.HasValue)
                 {
-                    info.InferTotalBitrate(true);
+                    var otherStreams = info.MediaStreams
+                        .Where(i => i.Type != MediaStreamType.Video && !i.IsExternal)
+                        .ToList();
+
+                    // Only attribute the leftover bitrate to the video stream if every audio stream's bitrate is known.
+                    var audioBitratesKnown = otherStreams
+                        .Where(i => i.Type == MediaStreamType.Audio)
+                        .All(i => i.BitRate.HasValue);
+
+                    if (audioBitratesKnown)
+                    {
+                        var estimatedVideoBitrate = info.Bitrate.Value - otherStreams.Sum(i => i.BitRate ?? 0);
+                        if (estimatedVideoBitrate > 0)
+                        {
+                            videoStreams[0].BitRate = estimatedVideoBitrate;
+                        }
+                    }
                 }
+
+                // If the container bitrate is still unknown, infer it from the sum of the streams.
+                info.InferTotalBitrate();
             }
 
             return info;
@@ -316,54 +338,34 @@ namespace MediaBrowser.MediaEncoding.Probing
             return string.Join(',', splitFormat.Where(s => !string.IsNullOrEmpty(s)));
         }
 
-        private static int? GetEstimatedAudioBitrate(string codec, int? channels)
+        internal static int? GetEstimatedAudioBitrate(string codec, string profile, int? channels)
         {
-            if (!channels.HasValue)
+            if (!channels.HasValue || channels.Value < 1 || string.IsNullOrEmpty(codec))
             {
                 return null;
             }
 
-            var channelsValue = channels.Value;
+            // Rough typical bitrates used only as a fallback when ffprobe doesn't report a stream bitrate.
+            var channelCount = channels.Value;
+            var isMultichannel = channelCount > 2;
 
-            if (string.Equals(codec, "aac", StringComparison.OrdinalIgnoreCase)
-                || string.Equals(codec, "mp3", StringComparison.OrdinalIgnoreCase))
+            return codec.ToLowerInvariant() switch
             {
-                switch (channelsValue)
-                {
-                    case <= 2:
-                        return 192000;
-                    case >= 5:
-                        return 320000;
-                }
-            }
-
-            if (string.Equals(codec, "ac3", StringComparison.OrdinalIgnoreCase)
-                || string.Equals(codec, "eac3", StringComparison.OrdinalIgnoreCase))
-            {
-                switch (channelsValue)
-                {
-                    case <= 2:
-                        return 192000;
-                    case >= 5:
-                        return 640000;
-                }
-            }
-
-            if (string.Equals(codec, "flac", StringComparison.OrdinalIgnoreCase)
-                || string.Equals(codec, "alac", StringComparison.OrdinalIgnoreCase))
-            {
-                switch (channelsValue)
-                {
-                    case <= 2:
-                        return 960000;
-                    case >= 5:
-                        return 2880000;
-                }
-            }
-
-            return null;
+                "aac" or "mp3" or "mp2" => isMultichannel ? 320000 : 192000,
+                "ac3" or "eac3" => isMultichannel ? 640000 : 192000,
+                "dts" or "dca" => IsDtsLossless(profile) ? channelCount * 700000 : (isMultichannel ? 1509000 : 768000),
+                "opus" => isMultichannel ? 256000 : 128000,
+                "vorbis" => isMultichannel ? 320000 : 160000,
+                "wmav1" or "wmav2" or "wmapro" => isMultichannel ? 384000 : 192000,
+                "flac" or "alac" => channelCount * 480000,
+                "truehd" or "mlp" => channelCount * 700000,
+                _ => null
+            };
         }
 
+        private static bool IsDtsLossless(string profile)
+            => profile is not null && profile.Contains("HD MA", StringComparison.OrdinalIgnoreCase);
+
         private void FetchFromItunesInfo(string xml, MediaInfo info)
         {
             // Make things simpler and strip out the dtd
@@ -972,10 +974,12 @@ namespace MediaBrowser.MediaEncoding.Probing
                 bitrate = value;
             }
 
-            // The bitrate info of FLAC musics and some videos is included in formatInfo.
+            // The bitrate info of FLAC audio is included in formatInfo.
+            // Don't do this for video streams: formatInfo.BitRate is the overall container
+            // bitrate (video + audio + subtitles + overhead), not the video bitrate.
             if (bitrate == 0
                 && formatInfo is not null
-                && (stream.Type == MediaStreamType.Video || (isAudio && stream.Type == MediaStreamType.Audio)))
+                && isAudio && stream.Type == MediaStreamType.Audio)
             {
                 // If the stream info doesn't have a bitrate get the value from the media format info
                 if (int.TryParse(formatInfo.BitRate, CultureInfo.InvariantCulture, out value))
@@ -1260,9 +1264,16 @@ namespace MediaBrowser.MediaEncoding.Probing
             }
 
             var duration = GetDictionaryValue(streamInfo.Tags, "DURATION-eng") ?? GetDictionaryValue(streamInfo.Tags, "DURATION");
-            if (TimeSpan.TryParse(duration, out var parsedDuration))
+            if (!string.IsNullOrEmpty(duration))
             {
-                return parsedDuration.TotalSeconds;
+                // Matroska DURATION tags use nanosecond precision (e.g. "00:00:05.023000000"), but
+                // TimeSpan only supports up to 7 fractional digits (ticks). Trim the surplus digits so
+                // these durations parse instead of being silently dropped.
+                duration = DurationOverPrecisionRegex().Replace(duration, "$1");
+                if (TimeSpan.TryParse(duration, CultureInfo.InvariantCulture, out var parsedDuration))
+                {
+                    return parsedDuration.TotalSeconds;
+                }
             }
 
             return null;
@@ -1630,7 +1641,7 @@ namespace MediaBrowser.MediaEncoding.Probing
 
             // Credit to MCEBuddy: https://mcebuddy2x.codeplex.com/
             // DateTime is reported along with timezone info (typically Z i.e. UTC hence assume None)
-            if (tags.TryGetValue("WM/MediaOriginalBroadcastDateTime", out var premiereDateString) && DateTime.TryParse(year, null, DateTimeStyles.AdjustToUniversal, out var parsedDate))
+            if (tags.TryGetValue("WM/MediaOriginalBroadcastDateTime", out var premiereDateString) && DateTime.TryParse(year, CultureInfo.InvariantCulture, DateTimeStyles.AdjustToUniversal, out var parsedDate))
             {
                 video.PremiereDate = parsedDate;
             }
@@ -1764,5 +1775,8 @@ namespace MediaBrowser.MediaEncoding.Probing
 
         [GeneratedRegex("(?<name>.*) \\((?<instrument>.*)\\)")]
         private static partial Regex PerformerRegex();
+
+        [GeneratedRegex(@"(\.\d{7})\d+")]
+        private static partial Regex DurationOverPrecisionRegex();
     }
 }

MediaBrowser.Model/Dto/MediaSourceInfo.cs

@@ -55,6 +55,11 @@ namespace MediaBrowser.Model.Dto
 
         public long? RunTimeTicks { get; set; }
 
+        /// <summary>
+        /// Gets or sets the playback position for this specific source.
+        /// </summary>
+        public long? PlaybackPositionTicks { get; set; }
+
         public bool ReadAtNativeFramerate { get; set; }
 
         public bool IgnoreDts { get; set; }

MediaBrowser.Providers/Books/ComicServiceRegistrator.cs

@@ -1,23 +0,0 @@
-using MediaBrowser.Controller;
-using MediaBrowser.Controller.Plugins;
-using MediaBrowser.Providers.Books.ComicBookInfo;
-using MediaBrowser.Providers.Books.ComicInfo;
-using Microsoft.Extensions.DependencyInjection;
-
-namespace MediaBrowser.Providers.Books;
-
-/// <inheritdoc />
-public class ComicServiceRegistrator : IPluginServiceRegistrator
-{
-    /// <inheritdoc />
-    public void RegisterServices(IServiceCollection serviceCollection, IServerApplicationHost applicationHost)
-    {
-        // register the generic local metadata provider for comic files
-        serviceCollection.AddSingleton<ComicProvider>();
-
-        // register the actual implementations of the local metadata provider for comic files
-        serviceCollection.AddSingleton<IComicProvider, ComicBookInfoProvider>();
-        serviceCollection.AddSingleton<IComicProvider, ExternalComicInfoProvider>();
-        serviceCollection.AddSingleton<IComicProvider, InternalComicInfoProvider>();
-    }
-}

MediaBrowser.Providers/Books/OpenPackagingFormat/OpfReader.cs

@@ -125,7 +125,7 @@ namespace MediaBrowser.Providers.Books.OpenPackagingFormat
 
             ReadStringInto("//dc:date", date =>
             {
-                if (DateTime.TryParse(date, out var dateValue))
+                if (DateTime.TryParse(date, CultureInfo.InvariantCulture, out var dateValue))
                 {
                     book.PremiereDate = dateValue.Date;
                     book.ProductionYear = dateValue.Date.Year;

MediaBrowser.Providers/Manager/ImageSaver.cs

@@ -90,7 +90,7 @@ namespace MediaBrowser.Providers.Manager
         {
             ArgumentException.ThrowIfNullOrEmpty(mimeType);
 
-            var saveLocally = item.SupportsLocalMetadata && item.IsSaveLocalMetadataEnabled() && !item.ExtraType.HasValue && item is not Audio;
+            var saveLocally = item.SupportsLocalMetadata && item.IsSaveLocalMetadataEnabled() && !item.ExtraType.HasValue && (item is AudioBook || item is not Audio);
 
             if (type != ImageType.Primary && item is Episode)
             {

MediaBrowser.Providers/MediaInfo/AudioFileProber.cs

@@ -549,7 +549,7 @@ namespace MediaBrowser.Providers.MediaInfo
             var candidateUnsynchronizedLyric = supportedLyrics.FirstOrDefault(l => l.Format is LyricsInfo.LyricsFormat.UNSYNCHRONIZED or LyricsInfo.LyricsFormat.OTHER && l.UnsynchronizedLyrics is not null);
             var lyrics = candidateSynchronizedLyric is not null ? candidateSynchronizedLyric.FormatSynch() : candidateUnsynchronizedLyric?.UnsynchronizedLyrics;
             if (!string.IsNullOrWhiteSpace(lyrics)
-                && tryExtractEmbeddedLyrics)
+                && (tryExtractEmbeddedLyrics || options.ReplaceAllMetadata))
             {
                 await _lyricManager.SaveLyricAsync(audio, "lrc", lyrics).ConfigureAwait(false);
             }

MediaBrowser.Providers/TV/SeriesMetadataService.cs

@@ -78,11 +78,73 @@ public class SeriesMetadataService : MetadataService<Series, SeriesInfo>
     {
         await base.AfterMetadataRefresh(item, refreshOptions, cancellationToken).ConfigureAwait(false);
 
+        // Note that this only updates the children's SeriesPresentationUniqueKey and SeasonId, not the ParentIndexNumber
+        if (LibraryManager.GetLibraryOptions(item).EnableAutomaticSeriesGrouping)
+        {
+            await UpdateSeriesChildrenInfoAsync(item, cancellationToken).ConfigureAwait(false);
+        }
+
         RemoveObsoleteEpisodes(item);
         RemoveObsoleteSeasons(item);
         await CreateSeasonsAsync(item, cancellationToken).ConfigureAwait(false);
     }
 
+    /// <summary>
+    /// Reconciles seasons and episodes with the series' finalized state.
+    /// </summary>
+    /// <remarks>
+    /// The series' presentation unique key can change during a refresh once provider ids become
+    /// available - notably with <c>EnableAutomaticSeriesGrouping</c>, where the key is derived from
+    /// the provider id and the owning libraries instead of the (immutable) item id. Seasons and
+    /// episodes cache this value in <see cref="IHasSeries.SeriesPresentationUniqueKey"/> and are
+    /// matched to (and displayed under) the series by it, so any child left with a stale key - or an
+    /// episode not yet linked to a freshly created season - stays hidden until a later scan. Syncing
+    /// them against the series here lets everything appear within a single scan.
+    /// </remarks>
+    /// <param name="series">The series.</param>
+    /// <param name="cancellationToken">The cancellation token.</param>
+    /// <returns>The async task.</returns>
+    private async Task UpdateSeriesChildrenInfoAsync(Series series, CancellationToken cancellationToken)
+    {
+        // Reload children so episode numbers / seasons persisted earlier in the refresh are seen.
+        series.Children = null;
+        var seriesKey = series.GetPresentationUniqueKey();
+        var children = series.GetRecursiveChildren(i => i is Season || i is Episode);
+        var seasons = children.OfType<Season>().ToList();
+
+        foreach (var child in children)
+        {
+            var updateType = ItemUpdateType.None;
+
+            if (child is IHasSeries hasSeries
+                && !string.Equals(hasSeries.SeriesPresentationUniqueKey, seriesKey, StringComparison.Ordinal))
+            {
+                hasSeries.SeriesPresentationUniqueKey = seriesKey;
+                updateType |= ItemUpdateType.MetadataImport;
+            }
+
+            if (child is Episode episode)
+            {
+                var seasonId = episode.FindSeasonId();
+                if (seasonId.IsEmpty() && episode.ParentIndexNumber.HasValue)
+                {
+                    seasonId = seasons.Find(s => s.IndexNumber == episode.ParentIndexNumber)?.Id ?? Guid.Empty;
+                }
+
+                if (!seasonId.IsEmpty() && !episode.SeasonId.Equals(seasonId))
+                {
+                    episode.SeasonId = seasonId;
+                    updateType |= ItemUpdateType.MetadataImport;
+                }
+            }
+
+            if (updateType > ItemUpdateType.None)
+            {
+                await child.UpdateToRepositoryAsync(updateType, cancellationToken).ConfigureAwait(false);
+            }
+        }
+    }
+
     /// <inheritdoc />
     protected override void MergeData(MetadataResult<Series> source, MetadataResult<Series> target, MetadataField[] lockedFields, bool replaceData, bool mergeMetadataSettings)
     {
@@ -235,6 +297,28 @@ public class SeriesMetadataService : MetadataService<Series, SeriesInfo>
     private async Task CreateSeasonsAsync(Series series, CancellationToken cancellationToken)
     {
         var seriesChildren = series.GetRecursiveChildren(i => i is Episode || i is Season);
+
+        // CreateSeasonsAsync can run before the episodes themselves have been refreshed during an
+        // initial scan, so their ParentIndexNumber may still be unset. Resolve the season number
+        // from the path first to avoid creating a premature "Season Unknown" instead of the real
+        // season for episodes that live directly in a flat series folder.
+        foreach (var episode in seriesChildren.OfType<Episode>())
+        {
+            if (episode.ParentIndexNumber.HasValue)
+            {
+                continue;
+            }
+
+            try
+            {
+                LibraryManager.FillMissingEpisodeNumbersFromPath(episode, false);
+            }
+            catch (Exception ex)
+            {
+                Logger.LogError(ex, "Error resolving season number from path for {Path}", episode.Path);
+            }
+        }
+
         var seasons = seriesChildren.OfType<Season>().ToList();
         var episodes = seriesChildren.OfType<Episode>().ToList();
 

src/Jellyfin.LiveTv/Channels/ChannelManager.cs

@@ -14,6 +14,7 @@ using Jellyfin.Database.Implementations.Entities;
 using Jellyfin.Database.Implementations.Enums;
 using Jellyfin.Extensions;
 using Jellyfin.Extensions.Json;
+using Jellyfin.LiveTv;
 using MediaBrowser.Common.Extensions;
 using MediaBrowser.Controller.Channels;
 using MediaBrowser.Controller.Configuration;
@@ -1109,9 +1110,8 @@ namespace Jellyfin.LiveTv.Channels
                 item.Path = mediaSource?.Path;
             }
 
-            if (!string.IsNullOrEmpty(info.ImageUrl) && !item.HasImage(ImageType.Primary))
+            if (LiveTvChannelImageHelper.UpdateChannelImageIfNeeded(item, null, info.ImageUrl))
             {
-                item.SetImagePath(ImageType.Primary, info.ImageUrl);
                 _logger.LogDebug("Forcing update due to ImageUrl {0}", item.Name);
                 forceUpdate = true;
             }

src/Jellyfin.LiveTv/Guide/GuideManager.cs

@@ -5,6 +5,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using Jellyfin.Data.Enums;
 using Jellyfin.Extensions;
+using Jellyfin.LiveTv;
 using Jellyfin.LiveTv.Configuration;
 using MediaBrowser.Common.Configuration;
 using MediaBrowser.Controller.Dto;
@@ -448,23 +449,9 @@ public class GuideManager : IGuideManager
 
         item.Name = channelInfo.Name;
 
-        var currentPrimary = item.GetImageInfo(ImageType.Primary, 0);
-        var imageUrlIsNull = string.IsNullOrWhiteSpace(channelInfo.ImageUrl);
-
-        // Update channel image if image URL has changed
-        if (currentPrimary is null
-            || (!imageUrlIsNull && !string.Equals(currentPrimary.Path, channelInfo.ImageUrl, StringComparison.Ordinal)))
+        if (LiveTvChannelImageHelper.UpdateChannelImageIfNeeded(item, channelInfo.ImagePath, channelInfo.ImageUrl))
         {
-            if (!string.IsNullOrWhiteSpace(channelInfo.ImagePath))
-            {
-                item.SetImagePath(ImageType.Primary, channelInfo.ImagePath);
-                forceUpdate = true;
-            }
-            else if (!imageUrlIsNull)
-            {
-                item.SetImagePath(ImageType.Primary, channelInfo.ImageUrl);
-                forceUpdate = true;
-            }
+            forceUpdate = true;
         }
 
         if (isNew)

src/Jellyfin.LiveTv/Listings/SchedulesDirect.cs

@@ -748,9 +748,7 @@ namespace Jellyfin.LiveTv.Listings
 #pragma warning disable CA5350 // SchedulesDirect is always SHA1.
             var hashedPasswordBytes = SHA1.HashData(Encoding.ASCII.GetBytes(password));
 #pragma warning restore CA5350
-            // TODO: remove ToLower when Convert.ToHexString supports lowercase
-            // Schedules Direct requires the hex to be lowercase
-            string hashedPassword = Convert.ToHexString(hashedPasswordBytes).ToLowerInvariant();
+            string hashedPassword = Convert.ToHexStringLower(hashedPasswordBytes);
             options.Content = new StringContent("{\"username\":\"" + username + "\",\"password\":\"" + hashedPassword + "\"}", Encoding.UTF8, MediaTypeNames.Application.Json);
 
             var root = await Request<TokenDto>(options, false, null, cancellationToken).ConfigureAwait(false);

src/Jellyfin.LiveTv/LiveTvChannelImageHelper.cs

@@ -0,0 +1,33 @@
+using MediaBrowser.Controller.Entities;
+using MediaBrowser.Model.Entities;
+
+namespace Jellyfin.LiveTv;
+
+/// <summary>
+/// Helpers for keeping Live TV channel icons in sync with guide data.
+/// </summary>
+internal static class LiveTvChannelImageHelper
+{
+    /// <summary>
+    /// Applies the channel icon from guide or tuner metadata.
+    /// Called on each guide refresh so remote icons are re-downloaded even when the URL is unchanged.
+    /// </summary>
+    /// <param name="item">The channel item.</param>
+    /// <param name="imagePath">The local image path from the tuner, if any.</param>
+    /// <param name="imageUrl">The remote image URL from the guide provider, if any.</param>
+    /// <returns><c>true</c> when the item image metadata was updated.</returns>
+    internal static bool UpdateChannelImageIfNeeded(BaseItem item, string? imagePath, string? imageUrl)
+    {
+        var newImageSource = !string.IsNullOrWhiteSpace(imagePath)
+            ? imagePath
+            : imageUrl;
+
+        if (string.IsNullOrWhiteSpace(newImageSource))
+        {
+            return false;
+        }
+
+        item.SetImagePath(ImageType.Primary, newImageSource);
+        return true;
+    }
+}

tests/Jellyfin.Controller.Tests/Entities/BaseItemTests.cs

@@ -1,6 +1,15 @@
 using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using System.Threading;
+using Jellyfin.Database.Implementations.Entities;
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Library;
+using MediaBrowser.Controller.LiveTv;
+using MediaBrowser.Controller.MediaSegments;
+using MediaBrowser.Model.Dto;
+using MediaBrowser.Model.Entities;
 using MediaBrowser.Model.MediaInfo;
 using Moq;
 using Xunit;
@@ -46,4 +55,284 @@ public class BaseItemTests
         Assert.Equal(name, video.GetMediaSourceName(video));
         Assert.Equal(altName, video.GetMediaSourceName(videoAlt));
     }
+
+    [Theory]
+    // Episode versions share a season folder; the common prefix (not the folder name) yields the label.
+    // Both files carry a suffix (no bare base name), so the shared "- " must be stripped too.
+    [InlineData(
+        "Spider-Noir - S01E02 - Wo ist Flint - Greyscale",
+        "Spider-Noir - S01E02 - Wo ist Flint - Colorized",
+        "Greyscale",
+        "Colorized")]
+    // One version is the bare base name; the other is suffixed.
+    [InlineData(
+        "Spider-Noir - S01E02 - Wo ist Flint",
+        "Spider-Noir - S01E02 - Wo ist Flint - Greyscale",
+        "Spider-Noir - S01E02 - Wo ist Flint",
+        "Greyscale")]
+    // Suffixes share a leading word ("Grey"); the prefix must retreat to the separator, not split it.
+    [InlineData(
+        "Demo - S01E01 - Greyscale",
+        "Demo - S01E01 - Greyish",
+        "Greyscale",
+        "Greyish")]
+    // Underscore separator.
+    [InlineData("Movie (2020)_4K", "Movie (2020)_1080p", "4K", "1080p")]
+    // Dot separator.
+    [InlineData("Movie (2020).UHD", "Movie (2020).1080p", "UHD", "1080p")]
+    // Resolution variants that share leading digits must retreat to the separator, not yield "p"/"i".
+    [InlineData("Movie - 1080p", "Movie - 1080i", "1080p", "1080i")]
+    // A token shared by the descriptors but separated only by spaces (the resolution) must stay in the
+    // label: retreat to the '-' delimiter, not the interior space, so the resolution is kept.
+    [InlineData(
+        "movie (2020) - 2160p Extended",
+        "movie (2020) - 2160p Original",
+        "2160p Extended",
+        "2160p Original")]
+    // Bracketed version labels: the opening bracket is kept in the label.
+    [InlineData(
+        "Blade Runner (1982) [Final Cut] [1080p HEVC AAC]",
+        "Blade Runner (1982) [EE by ADM] [480p HEVC AAC]",
+        "[Final Cut] [1080p HEVC AAC]",
+        "[EE by ADM] [480p HEVC AAC]")]
+    public void GetMediaSourceName_CommonPrefix_Valid(string primaryName, string altName, string expectedPrimary, string expectedAlt)
+    {
+        var primaryPath = "/Shows/Demo/Season 01/" + primaryName + ".mkv";
+        var altPath = "/Shows/Demo/Season 01/" + altName + ".mkv";
+        var commonPrefix = BaseItem.GetCommonVersionPrefix([primaryName, altName]);
+
+        var video = new Video()
+        {
+            Path = primaryPath
+        };
+
+        var videoAlt = new Video()
+        {
+            Path = altPath,
+        };
+
+        var mediaSourceManager = new Mock<IMediaSourceManager>();
+        mediaSourceManager.Setup(x => x.GetPathProtocol(It.IsAny<string>()))
+                .Returns((string x) => MediaProtocol.File);
+        var libraryManager = new Mock<ILibraryManager>();
+        // No local alternate versions: these are linked (separate items), so the folder fallback is unavailable.
+        libraryManager.Setup(x => x.GetLocalAlternateVersionIds(It.IsAny<Video>()))
+                .Returns(Array.Empty<Guid>());
+        BaseItem.MediaSourceManager = mediaSourceManager.Object;
+        BaseItem.LibraryManager = libraryManager.Object;
+
+        Assert.Equal(expectedPrimary, video.GetMediaSourceName(video, commonPrefix));
+        Assert.Equal(expectedAlt, videoAlt.GetMediaSourceName(videoAlt, commonPrefix));
+    }
+
+    [Fact]
+    public void GetAlternateVersion_ReturnsMatchingLocalVersion()
+    {
+        var (primary, alt1, alt2) = SetupVersionGroup();
+
+        Assert.Same(alt1, primary.GetAlternateVersion(alt1.Id));
+        Assert.Same(alt2, primary.GetAlternateVersion(alt2.Id));
+        Assert.Same(primary, primary.GetAlternateVersion(primary.Id));
+        Assert.Null(primary.GetAlternateVersion(Guid.NewGuid()));
+    }
+
+    [Fact]
+    public void GetAllVersions_FromAnyVersion_ReturnsEveryVersionOnce()
+    {
+        var (primary, alt1, alt2) = SetupVersionGroup();
+
+        foreach (var source in new[] { primary, alt1, alt2 })
+        {
+            var versions = source.GetAllVersions();
+
+            Assert.Equal(3, versions.Count);
+            Assert.Contains(versions, v => v.Id.Equals(primary.Id));
+            Assert.Contains(versions, v => v.Id.Equals(alt1.Id));
+            Assert.Contains(versions, v => v.Id.Equals(alt2.Id));
+        }
+    }
+
+    [Fact]
+    public void PropagatePlayedState_MarksAlternateVersions_AndResetsPositionByDefault()
+    {
+        var (primary, alt1, alt2) = SetupVersionGroup();
+
+        var saved = CaptureSaves();
+
+        var user = new User("test", "default", "default");
+        primary.PropagatePlayedState(user, true);
+
+        // Both alternate versions are marked played, the primary (self) is not, and the position is
+        // reset so a watched version does not linger in "Continue Watching".
+        Assert.Equal(2, saved.Count);
+        Assert.DoesNotContain(saved, e => e.ItemId.Equals(primary.Id));
+        Assert.Contains(saved, e => e.ItemId.Equals(alt1.Id));
+        Assert.Contains(saved, e => e.ItemId.Equals(alt2.Id));
+        Assert.All(saved, e =>
+        {
+            Assert.True(e.Dto.Played.GetValueOrDefault());
+            Assert.Equal(0, e.Dto.PlaybackPositionTicks);
+        });
+    }
+
+    [Fact]
+    public void PropagatePlayedState_WithoutReset_LeavesPositionUntouched()
+    {
+        var (primary, _, _) = SetupVersionGroup();
+
+        var saved = CaptureSaves();
+
+        primary.PropagatePlayedState(new User("test", "default", "default"), true, resetPosition: false);
+
+        Assert.Equal(2, saved.Count);
+        Assert.All(saved, e =>
+        {
+            Assert.True(e.Dto.Played.GetValueOrDefault());
+            Assert.Null(e.Dto.PlaybackPositionTicks);
+        });
+    }
+
+    [Fact]
+    public void PropagatePlayedState_Unwatched_ClearsAllWatchedStateOnVersions()
+    {
+        var (primary, alt1, alt2) = SetupVersionGroup();
+
+        // Each alternate starts out watched, with a play count, resume point and last-played date.
+        var existing = new Dictionary<Guid, UserItemData>
+        {
+            [alt1.Id] = new UserItemData { Key = "alt1", Played = true, PlayCount = 3, PlaybackPositionTicks = 1000, LastPlayedDate = new DateTime(2020, 1, 1, 0, 0, 0, DateTimeKind.Utc) },
+            [alt2.Id] = new UserItemData { Key = "alt2", Played = true, PlayCount = 1, PlaybackPositionTicks = 500, LastPlayedDate = new DateTime(2021, 2, 2, 0, 0, 0, DateTimeKind.Utc) },
+        };
+
+        var saved = new List<UserItemData>();
+        var userDataManager = new Mock<IUserDataManager>();
+        userDataManager.Setup(x => x.GetUserData(It.IsAny<User>(), It.IsAny<BaseItem>()))
+            .Returns((User _, BaseItem item) => existing.GetValueOrDefault(item.Id));
+        userDataManager
+            .Setup(x => x.SaveUserData(It.IsAny<User>(), It.IsAny<BaseItem>(), It.IsAny<UserItemData>(), It.IsAny<UserDataSaveReason>(), It.IsAny<CancellationToken>()))
+            .Callback<User, BaseItem, UserItemData, UserDataSaveReason, CancellationToken>((_, _, data, _, _) => saved.Add(data));
+        BaseItem.UserDataManager = userDataManager.Object;
+
+        primary.PropagatePlayedState(new User("test", "default", "default"), false);
+
+        // Every alternate is fully reset to an unwatched state, mirroring MarkUnplayed: the played flag,
+        // play count, resume point and last-played date are all cleared so no watched state lingers.
+        Assert.Equal(2, saved.Count);
+        Assert.All(saved, d =>
+        {
+            Assert.False(d.Played);
+            Assert.Equal(0, d.PlayCount);
+            Assert.Equal(0, d.PlaybackPositionTicks);
+            Assert.Null(d.LastPlayedDate);
+        });
+    }
+
+    private static List<(Guid ItemId, UpdateUserItemDataDto Dto)> CaptureSaves()
+    {
+        var saved = new List<(Guid ItemId, UpdateUserItemDataDto Dto)>();
+        var userDataManager = new Mock<IUserDataManager>();
+        userDataManager
+            .Setup(x => x.SaveUserData(It.IsAny<User>(), It.IsAny<BaseItem>(), It.IsAny<UpdateUserItemDataDto>(), It.IsAny<UserDataSaveReason>()))
+            .Callback<User, BaseItem, UpdateUserItemDataDto, UserDataSaveReason>((_, item, dto, _) => saved.Add((item.Id, dto)));
+        BaseItem.UserDataManager = userDataManager.Object;
+        return saved;
+    }
+
+    [Fact]
+    public void PropagatePlayedState_SingleVersion_DoesNothing()
+    {
+        var solo = new Video { Id = Guid.NewGuid(), Path = "/Movies/Solo/Solo.mkv" };
+
+        var mediaSourceManager = new Mock<IMediaSourceManager>();
+        mediaSourceManager.Setup(x => x.GetPathProtocol(It.IsAny<string>())).Returns(MediaProtocol.File);
+        var libraryManager = new Mock<ILibraryManager>();
+        libraryManager.Setup(x => x.GetLocalAlternateVersionIds(It.IsAny<Video>())).Returns(Array.Empty<Guid>());
+        libraryManager.Setup(x => x.GetLinkedAlternateVersions(It.IsAny<Video>())).Returns(Array.Empty<Video>());
+        BaseItem.MediaSourceManager = mediaSourceManager.Object;
+        BaseItem.LibraryManager = libraryManager.Object;
+
+        var userDataManager = new Mock<IUserDataManager>();
+        BaseItem.UserDataManager = userDataManager.Object;
+
+        solo.PropagatePlayedState(new User("test", "default", "default"), true);
+
+        userDataManager.Verify(
+            x => x.SaveUserData(It.IsAny<User>(), It.IsAny<BaseItem>(), It.IsAny<UpdateUserItemDataDto>(), It.IsAny<UserDataSaveReason>()),
+            Times.Never);
+    }
+
+    private static (Video Primary, Video Alt1, Video Alt2) SetupVersionGroup()
+    {
+        var primary = new Video { Id = Guid.NewGuid(), Path = "/Movies/Movie/Movie.mkv" };
+        var alt1 = new Video { Id = Guid.NewGuid(), Path = "/Movies/Movie/Movie - 1080p.mkv", PrimaryVersionId = primary.Id };
+        var alt2 = new Video { Id = Guid.NewGuid(), Path = "/Movies/Movie/Movie - 4K.mkv", PrimaryVersionId = primary.Id };
+
+        // 2160p primary, 1080p alternates: width is only the ordering tiebreaker, set so it would place
+        // the primary first — letting the tests confirm the queried version's own source still wins.
+        var widths = new Dictionary<Guid, int> { [primary.Id] = 3840, [alt1.Id] = 1920, [alt2.Id] = 1920 };
+        var mediaSourceManager = new Mock<IMediaSourceManager>();
+        mediaSourceManager.Setup(x => x.GetPathProtocol(It.IsAny<string>())).Returns(MediaProtocol.File);
+        mediaSourceManager.Setup(x => x.GetMediaStreams(It.IsAny<Guid>()))
+            .Returns((Guid id) => new List<MediaStream> { new MediaStream { Type = MediaStreamType.Video, Width = widths.GetValueOrDefault(id) } });
+        mediaSourceManager.Setup(x => x.GetMediaAttachments(It.IsAny<Guid>())).Returns(new List<MediaAttachment>());
+
+        var segmentManager = new Mock<IMediaSegmentManager>();
+        segmentManager.Setup(x => x.IsTypeSupported(It.IsAny<BaseItem>())).Returns(false);
+        BaseItem.MediaSegmentManager = segmentManager.Object;
+
+        var libraryManager = new Mock<ILibraryManager>();
+        libraryManager.Setup(x => x.GetLinkedAlternateVersions(It.IsAny<Video>())).Returns(Array.Empty<Video>());
+        libraryManager.Setup(x => x.GetLocalAlternateVersionIds(primary)).Returns(new[] { alt1.Id, alt2.Id });
+        libraryManager.Setup(x => x.GetLocalAlternateVersionIds(alt1)).Returns(Array.Empty<Guid>());
+        libraryManager.Setup(x => x.GetLocalAlternateVersionIds(alt2)).Returns(Array.Empty<Guid>());
+        libraryManager.Setup(x => x.GetItemById(alt1.Id)).Returns(alt1);
+        libraryManager.Setup(x => x.GetItemById(alt2.Id)).Returns(alt2);
+        libraryManager.Setup(x => x.GetItemById(primary.Id)).Returns(primary);
+
+        var recordingsManager = new Mock<IRecordingsManager>();
+        recordingsManager.Setup(x => x.GetActiveRecordingInfo(It.IsAny<string>())).Returns((ActiveRecordingInfo?)null);
+        Video.RecordingsManager = recordingsManager.Object;
+
+        BaseItem.MediaSourceManager = mediaSourceManager.Object;
+        BaseItem.LibraryManager = libraryManager.Object;
+
+        return (primary, alt1, alt2);
+    }
+
+    [Fact]
+    public void GetMediaSources_DefaultsToTheQueriedVersionsOwnSource()
+    {
+        var (primary, alt1, _) = SetupVersionGroup();
+
+        // Resuming the 1080p alternate must default to the 1080p source, not the higher-resolution
+        // 2160p primary that the width ordering would otherwise place first.
+        Assert.Equal(alt1.Id.ToString("N"), alt1.GetMediaSources(false)[0].Id);
+
+        // Opening the primary still defaults to the primary's own (here highest-resolution) source.
+        Assert.Equal(primary.Id.ToString("N"), primary.GetMediaSources(false)[0].Id);
+    }
+
+    [Fact]
+    public void GetAllItemsForMediaSources_FromAnyVersion_HasNoDuplicates()
+    {
+        var (primary, alt1, alt2) = SetupVersionGroup();
+
+        var method = typeof(Video).GetMethod("GetAllItemsForMediaSources", BindingFlags.Instance | BindingFlags.NonPublic);
+        Assert.NotNull(method);
+
+        // Each version must surface exactly once, regardless of which member the list is built from.
+        // Building from an alternate previously re-added that alternate as a "local alternate" of the
+        // primary, producing a duplicate entry in the version dropdown.
+        foreach (var source in new[] { primary, alt1, alt2 })
+        {
+            var items = (IEnumerable<(BaseItem Item, MediaSourceType MediaSourceType)>)method!.Invoke(source, null)!;
+            var ids = items.Select(i => i.Item.Id).ToList();
+
+            Assert.Equal(3, ids.Count);
+            Assert.Equal(ids.Count, ids.Distinct().Count());
+            Assert.Contains(primary.Id, ids);
+            Assert.Contains(alt1.Id, ids);
+            Assert.Contains(alt2.Id, ids);
+        }
+    }
 }

tests/Jellyfin.Controller.Tests/Library/VersionResumeDataTests.cs

@@ -0,0 +1,89 @@
+using System;
+using MediaBrowser.Controller.Entities;
+using MediaBrowser.Controller.Library;
+using MediaBrowser.Model.Dto;
+using Xunit;
+
+namespace Jellyfin.Controller.Tests.Library;
+
+public class VersionResumeDataTests
+{
+    [Fact]
+    public void ApplyTo_CompletedOtherVersion_PropagatesCompletionAndClearsStaleResume()
+    {
+        var lastPlayed = new DateTime(2026, 1, 2, 0, 0, 0, DateTimeKind.Utc);
+        var resume = new VersionResumeData(
+            Guid.NewGuid(),
+            new UserItemData { Key = "version", PlaybackPositionTicks = 0, Played = true, LastPlayedDate = lastPlayed });
+
+        var dto = new UserItemDataDto { ItemId = Guid.NewGuid(), Key = "primary", PlaybackPositionTicks = 1, Played = false, PlayedPercentage = 50 };
+
+        resume.ApplyTo(dto);
+
+        // Completion state propagates to the primary...
+        Assert.True(dto.Played);
+        Assert.Equal(lastPlayed, dto.LastPlayedDate);
+
+        // ...and because the movie was finished on a different version, the primary's own stale resume bar is cleared.
+        Assert.Equal(0, dto.PlaybackPositionTicks);
+        Assert.Null(dto.PlayedPercentage);
+    }
+
+    [Fact]
+    public void ApplyTo_PrimaryOwnProgress_KeepsResumePosition()
+    {
+        var primaryId = Guid.NewGuid();
+        var lastPlayed = new DateTime(2026, 1, 2, 0, 0, 0, DateTimeKind.Utc);
+
+        // The winning version is the primary itself (e.g. rewatching): its resume bar must survive.
+        var resume = new VersionResumeData(
+            primaryId,
+            new UserItemData { Key = "primary", PlaybackPositionTicks = 5, Played = true, LastPlayedDate = lastPlayed });
+
+        var dto = new UserItemDataDto { ItemId = primaryId, Key = "primary", PlaybackPositionTicks = 5, Played = true, PlayedPercentage = 20 };
+
+        resume.ApplyTo(dto);
+
+        Assert.True(dto.Played);
+        Assert.Equal(5, dto.PlaybackPositionTicks);
+        Assert.Equal(20, dto.PlayedPercentage);
+    }
+
+    [Fact]
+    public void ApplyTo_InProgressOtherVersion_KeepsPrimaryResumePosition()
+    {
+        var lastPlayed = new DateTime(2026, 1, 2, 0, 0, 0, DateTimeKind.Utc);
+
+        // A different version that is in-progress (not finished) must not clear the primary's position.
+        var resume = new VersionResumeData(
+            Guid.NewGuid(),
+            new UserItemData { Key = "version", PlaybackPositionTicks = 25, Played = false, LastPlayedDate = lastPlayed });
+
+        var dto = new UserItemDataDto { ItemId = Guid.NewGuid(), Key = "primary", PlaybackPositionTicks = 1, Played = false, PlayedPercentage = 50 };
+
+        resume.ApplyTo(dto);
+
+        Assert.False(dto.Played);
+        Assert.Equal(1, dto.PlaybackPositionTicks);
+        Assert.Equal(50, dto.PlayedPercentage);
+    }
+
+    [Fact]
+    public void ApplyTo_DoesNotUnsetExistingPlayedOrRegressLastPlayed()
+    {
+        var primaryLastPlayed = new DateTime(2026, 1, 5, 0, 0, 0, DateTimeKind.Utc);
+        var versionLastPlayed = new DateTime(2026, 1, 2, 0, 0, 0, DateTimeKind.Utc);
+        var resume = new VersionResumeData(
+            Guid.NewGuid(),
+            new UserItemData { Key = "version", Played = false, LastPlayedDate = versionLastPlayed });
+
+        var dto = new UserItemDataDto { ItemId = Guid.NewGuid(), Key = "primary", Played = true, LastPlayedDate = primaryLastPlayed };
+
+        resume.ApplyTo(dto);
+
+        // A not-yet-completed version must not clear the primary's own completion, and the more recent
+        // LastPlayedDate is kept.
+        Assert.True(dto.Played);
+        Assert.Equal(primaryLastPlayed, dto.LastPlayedDate);
+    }
+}

tests/Jellyfin.LiveTv.Tests/LiveTvChannelImageHelperTests.cs

@@ -0,0 +1,51 @@
+using Jellyfin.LiveTv;
+using MediaBrowser.Controller.Entities;
+using MediaBrowser.Controller.LiveTv;
+using MediaBrowser.Model.Entities;
+using Xunit;
+
+namespace Jellyfin.LiveTv.Tests;
+
+public class LiveTvChannelImageHelperTests
+{
+    [Fact]
+    public void UpdateChannelImageIfNeeded_NoSource_DoesNotUpdate()
+    {
+        var channel = new LiveTvChannel { Name = "Test Channel" };
+
+        var updated = LiveTvChannelImageHelper.UpdateChannelImageIfNeeded(channel, null, null);
+
+        Assert.False(updated);
+        Assert.False(channel.HasImage(ImageType.Primary));
+    }
+
+    [Fact]
+    public void UpdateChannelImageIfNeeded_WithUrl_AppliesUrl()
+    {
+        var channel = new LiveTvChannel { Name = "Test Channel" };
+
+        var updated = LiveTvChannelImageHelper.UpdateChannelImageIfNeeded(
+            channel,
+            null,
+            "https://example.com/icon.png");
+
+        Assert.True(updated);
+        Assert.True(channel.HasImage(ImageType.Primary));
+        Assert.Equal("https://example.com/icon.png", channel.GetImagePath(ImageType.Primary));
+    }
+
+    [Fact]
+    public void UpdateChannelImageIfNeeded_SameUrl_StillUpdates()
+    {
+        var channel = new LiveTvChannel { Name = "Test Channel" };
+        LiveTvChannelImageHelper.UpdateChannelImageIfNeeded(channel, null, "https://example.com/icon.png");
+
+        var updated = LiveTvChannelImageHelper.UpdateChannelImageIfNeeded(
+            channel,
+            null,
+            "https://example.com/icon.png");
+
+        Assert.True(updated);
+        Assert.Equal("https://example.com/icon.png", channel.GetImagePath(ImageType.Primary));
+    }
+}

tests/Jellyfin.MediaEncoding.Tests/Probing/ProbeResultNormalizerTests.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Globalization;
 using System.IO;
+using System.Linq;
 using System.Text.Json;
 using Jellyfin.Data.Enums;
 using Jellyfin.Extensions.Json;
@@ -56,6 +57,43 @@ namespace Jellyfin.MediaEncoding.Tests.Probing
         public void IsNearSquarePixelSar_DetectsCorrectly(string? sar, bool expected)
             => Assert.Equal(expected, ProbeResultNormalizer.IsNearSquarePixelSar(sar));
 
+        [Theory]
+        // Lossy codecs, mono/stereo and multichannel.
+        [InlineData("aac", null, 2, 192000)]
+        [InlineData("mp3", null, 2, 192000)]
+        [InlineData("mp2", null, 2, 192000)]
+        [InlineData("aac", null, 6, 320000)]
+        [InlineData("ac3", null, 2, 192000)]
+        [InlineData("eac3", null, 6, 640000)]
+        [InlineData("opus", null, 2, 128000)]
+        [InlineData("vorbis", null, 6, 320000)]
+        [InlineData("wmav2", null, 2, 192000)]
+        // DTS: the lossy core (any non-MA profile, or none) is flat and caps at 5.1...
+        [InlineData("dts", null, 2, 768000)]
+        [InlineData("dts", "DTS", 6, 1509000)]
+        [InlineData("dts", "DTS-HD HRA", 8, 1509000)]
+        // ...while lossless DTS-HD MA scales per channel like other lossless codecs.
+        [InlineData("dts", "DTS-HD MA", 6, 4200000)]
+        [InlineData("dts", "DTS-HD MA + DTS:X", 8, 5600000)]
+        // Lossless codecs scale per channel.
+        [InlineData("flac", null, 2, 960000)]
+        [InlineData("flac", null, 6, 2880000)]
+        [InlineData("flac", null, 8, 3840000)]
+        [InlineData("alac", null, 6, 2880000)]
+        [InlineData("truehd", null, 2, 1400000)]
+        [InlineData("truehd", null, 6, 4200000)]
+        [InlineData("truehd", "Dolby TrueHD + Dolby Atmos", 8, 5600000)]
+        // 3-4 channel audio must use the multichannel estimate, not return null.
+        [InlineData("aac", null, 3, 320000)]
+        [InlineData("ac3", null, 4, 640000)]
+        // Codec matching is case-insensitive.
+        [InlineData("AAC", null, 2, 192000)]
+        // Unknown codec or unknown channel count cannot be estimated.
+        [InlineData("pcm_s16le", null, 2, null)]
+        [InlineData("aac", null, null, null)]
+        public void GetEstimatedAudioBitrate_ReturnsExpected(string codec, string? profile, int? channels, int? expected)
+            => Assert.Equal(expected, ProbeResultNormalizer.GetEstimatedAudioBitrate(codec, profile, channels));
+
         [Fact]
         public void GetMediaInfo_MetaData_Success()
         {
@@ -71,7 +109,10 @@ namespace Jellyfin.MediaEncoding.Tests.Probing
             Assert.Equal("4:3", res.VideoStream.AspectRatio);
             Assert.Equal(25f, res.VideoStream.AverageFrameRate);
             Assert.Equal(8, res.VideoStream.BitDepth);
-            Assert.Equal(69432, res.VideoStream.BitRate);
+            // ffprobe reports no per-stream video bitrate here. The container bitrate must not be
+            // misreported as the video bitrate, and the other streams' bitrates exceed the container
+            // bitrate in this sample, so no sensible video bitrate can be inferred (see #16248).
+            Assert.Null(res.VideoStream.BitRate);
             Assert.Equal("h264", res.VideoStream.Codec);
             Assert.Equal("1/50", res.VideoStream.CodecTimeBase);
             Assert.Equal(240, res.VideoStream.Height);
@@ -321,6 +362,73 @@ namespace Jellyfin.MediaEncoding.Tests.Probing
             Assert.True(res.VideoStream.IsDefault);
         }
 
+        [Fact]
+        public void GetMediaInfo_MissingVideoBitrate_EstimatedFromContainer()
+        {
+            // ffprobe did not report a per-stream video bitrate. The video bitrate must be estimated
+            // as the container bitrate minus the other (audio) stream bitrates, not reported as the
+            // whole container bitrate (see #16248).
+            var bytes = File.ReadAllBytes("Test Data/Probing/video_missing_video_bitrate.json");
+
+            var internalMediaInfoResult = JsonSerializer.Deserialize<InternalMediaInfoResult>(bytes, _jsonOptions);
+            MediaInfo res = _probeResultNormalizer.GetMediaInfo(internalMediaInfoResult, VideoType.VideoFile, false, "Test Data/Probing/video_missing_video_bitrate.mp4", MediaProtocol.File);
+
+            Assert.Equal(2, res.MediaStreams.Count);
+
+            Assert.NotNull(res.VideoStream);
+            Assert.Equal(MediaStreamType.Video, res.VideoStream.Type);
+
+            var audioStream = res.MediaStreams.First(i => i.Type == MediaStreamType.Audio);
+            Assert.Equal(128000, audioStream.BitRate);
+
+            // Container bitrate (5128000) minus the audio bitrate (128000).
+            Assert.Equal(5000000, res.VideoStream.BitRate);
+
+            // The container bitrate itself must remain the overall container bitrate.
+            Assert.Equal(5128000, res.Bitrate);
+        }
+
+        [Fact]
+        public void GetMediaInfo_NanosecondDurationTag_BitrateComputedFromBytes()
+        {
+            // The stream carries NUMBER_OF_BYTES and a nanosecond-precision DURATION tag but no
+            // bitrate. TimeSpan only supports 7 fractional digits, so the 9-digit DURATION must be
+            // trimmed for the duration to parse and the bitrate to be computed (bytes * 8 / seconds).
+            var bytes = File.ReadAllBytes("Test Data/Probing/video_nanosecond_duration_bitrate.json");
+
+            var internalMediaInfoResult = JsonSerializer.Deserialize<InternalMediaInfoResult>(bytes, _jsonOptions);
+            MediaInfo res = _probeResultNormalizer.GetMediaInfo(internalMediaInfoResult, VideoType.VideoFile, false, "Test Data/Probing/video_nanosecond_duration_bitrate.mkv", MediaProtocol.File);
+
+            Assert.NotNull(res.VideoStream);
+
+            // 10000000 bytes * 8 / 100 seconds.
+            Assert.Equal(800000, res.VideoStream.BitRate);
+        }
+
+        [Fact]
+        public void GetMediaInfo_MissingVideoBitrate_UnknownAudioBitrate_NotEstimated()
+        {
+            // ffprobe reported no per-stream video bitrate and the audio bitrate cannot be estimated
+            // (the audio stream has no channel count, so GetEstimatedAudioBitrate returns null). The
+            // video bitrate must be left unset rather than wrongly absorbing the unaccounted audio
+            // bitrate (see #16248).
+            var bytes = File.ReadAllBytes("Test Data/Probing/video_missing_video_bitrate_unknown_audio.json");
+
+            var internalMediaInfoResult = JsonSerializer.Deserialize<InternalMediaInfoResult>(bytes, _jsonOptions);
+            MediaInfo res = _probeResultNormalizer.GetMediaInfo(internalMediaInfoResult, VideoType.VideoFile, false, "Test Data/Probing/video_missing_video_bitrate_unknown_audio.mp4", MediaProtocol.File);
+
+            Assert.Equal(2, res.MediaStreams.Count);
+
+            Assert.NotNull(res.VideoStream);
+            Assert.Null(res.VideoStream.BitRate);
+
+            var audioStream = res.MediaStreams.First(i => i.Type == MediaStreamType.Audio);
+            Assert.Null(audioStream.BitRate);
+
+            // The overall container bitrate is still reported.
+            Assert.Equal(5128000, res.Bitrate);
+        }
+
         [Fact]
         public void GetMediaInfo_VideoWithSingleFrameMjpeg_Success()
         {

tests/Jellyfin.MediaEncoding.Tests/Test Data/Probing/video_missing_video_bitrate.json

@@ -0,0 +1,113 @@
+{
+    "streams": [
+        {
+            "index": 0,
+            "codec_name": "h264",
+            "codec_long_name": "H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10",
+            "profile": "High",
+            "codec_type": "video",
+            "codec_time_base": "1/48",
+            "codec_tag_string": "avc1",
+            "codec_tag": "0x31637661",
+            "width": 1920,
+            "height": 1080,
+            "coded_width": 1920,
+            "coded_height": 1080,
+            "closed_captions": 0,
+            "has_b_frames": 2,
+            "pix_fmt": "yuv420p",
+            "level": 40,
+            "chroma_location": "left",
+            "refs": 1,
+            "is_avc": "true",
+            "nal_length_size": "4",
+            "r_frame_rate": "24/1",
+            "avg_frame_rate": "24/1",
+            "time_base": "1/12288",
+            "start_pts": 0,
+            "start_time": "0.000000",
+            "duration_ts": 3686400,
+            "duration": "300.000000",
+            "bits_per_raw_sample": "8",
+            "nb_frames": "7200",
+            "disposition": {
+                "default": 1,
+                "dub": 0,
+                "original": 0,
+                "comment": 0,
+                "lyrics": 0,
+                "karaoke": 0,
+                "forced": 0,
+                "hearing_impaired": 0,
+                "visual_impaired": 0,
+                "clean_effects": 0,
+                "attached_pic": 0,
+                "timed_thumbnails": 0
+            },
+            "tags": {
+                "language": "und",
+                "handler_name": "VideoHandler"
+            }
+        },
+        {
+            "index": 1,
+            "codec_name": "aac",
+            "codec_long_name": "AAC (Advanced Audio Coding)",
+            "profile": "LC",
+            "codec_type": "audio",
+            "codec_time_base": "1/48000",
+            "codec_tag_string": "mp4a",
+            "codec_tag": "0x6134706d",
+            "sample_fmt": "fltp",
+            "sample_rate": "48000",
+            "channels": 2,
+            "channel_layout": "stereo",
+            "bits_per_sample": 0,
+            "r_frame_rate": "0/0",
+            "avg_frame_rate": "0/0",
+            "time_base": "1/48000",
+            "start_pts": 0,
+            "start_time": "0.000000",
+            "duration_ts": 14400000,
+            "duration": "300.000000",
+            "bit_rate": "128000",
+            "nb_frames": "14063",
+            "disposition": {
+                "default": 1,
+                "dub": 0,
+                "original": 0,
+                "comment": 0,
+                "lyrics": 0,
+                "karaoke": 0,
+                "forced": 0,
+                "hearing_impaired": 0,
+                "visual_impaired": 0,
+                "clean_effects": 0,
+                "attached_pic": 0,
+                "timed_thumbnails": 0
+            },
+            "tags": {
+                "language": "eng",
+                "handler_name": "SoundHandler"
+            }
+        }
+    ],
+    "format": {
+        "filename": "test.1080p.mp4",
+        "nb_streams": 2,
+        "nb_programs": 0,
+        "format_name": "mov,mp4,m4a,3gp,3g2,mj2",
+        "format_long_name": "QuickTime / MOV",
+        "start_time": "0.000000",
+        "duration": "300.000000",
+        "size": "192000000",
+        "bit_rate": "5128000",
+        "probe_score": 100,
+        "tags": {
+            "major_brand": "isom",
+            "minor_version": "512",
+            "compatible_brands": "isomiso2avc1mp41",
+            "encoder": "Lavf58.20.100"
+        }
+    }
+}

tests/Jellyfin.MediaEncoding.Tests/Test Data/Probing/video_missing_video_bitrate_unknown_audio.json

@@ -0,0 +1,110 @@
+{
+    "streams": [
+        {
+            "index": 0,
+            "codec_name": "h264",
+            "codec_long_name": "H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10",
+            "profile": "High",
+            "codec_type": "video",
+            "codec_time_base": "1/48",
+            "codec_tag_string": "avc1",
+            "codec_tag": "0x31637661",
+            "width": 1920,
+            "height": 1080,
+            "coded_width": 1920,
+            "coded_height": 1080,
+            "closed_captions": 0,
+            "has_b_frames": 2,
+            "pix_fmt": "yuv420p",
+            "level": 40,
+            "chroma_location": "left",
+            "refs": 1,
+            "is_avc": "true",
+            "nal_length_size": "4",
+            "r_frame_rate": "24/1",
+            "avg_frame_rate": "24/1",
+            "time_base": "1/12288",
+            "start_pts": 0,
+            "start_time": "0.000000",
+            "duration_ts": 3686400,
+            "duration": "300.000000",
+            "bits_per_raw_sample": "8",
+            "nb_frames": "7200",
+            "disposition": {
+                "default": 1,
+                "dub": 0,
+                "original": 0,
+                "comment": 0,
+                "lyrics": 0,
+                "karaoke": 0,
+                "forced": 0,
+                "hearing_impaired": 0,
+                "visual_impaired": 0,
+                "clean_effects": 0,
+                "attached_pic": 0,
+                "timed_thumbnails": 0
+            },
+            "tags": {
+                "language": "und",
+                "handler_name": "VideoHandler"
+            }
+        },
+        {
+            "index": 1,
+            "codec_name": "dts",
+            "codec_long_name": "DCA (DTS Coherent Acoustics)",
+            "profile": "DTS-HD MA",
+            "codec_type": "audio",
+            "codec_time_base": "1/48000",
+            "codec_tag_string": "[0][0][0][0]",
+            "codec_tag": "0x0000",
+            "sample_fmt": "s32p",
+            "sample_rate": "48000",
+            "bits_per_sample": 0,
+            "r_frame_rate": "0/0",
+            "avg_frame_rate": "0/0",
+            "time_base": "1/48000",
+            "start_pts": 0,
+            "start_time": "0.000000",
+            "duration_ts": 14400000,
+            "duration": "300.000000",
+            "nb_frames": "14063",
+            "disposition": {
+                "default": 1,
+                "dub": 0,
+                "original": 0,
+                "comment": 0,
+                "lyrics": 0,
+                "karaoke": 0,
+                "forced": 0,
+                "hearing_impaired": 0,
+                "visual_impaired": 0,
+                "clean_effects": 0,
+                "attached_pic": 0,
+                "timed_thumbnails": 0
+            },
+            "tags": {
+                "language": "eng",
+                "handler_name": "SoundHandler"
+            }
+        }
+    ],
+    "format": {
+        "filename": "test.1080p.mp4",
+        "nb_streams": 2,
+        "nb_programs": 0,
+        "format_name": "mov,mp4,m4a,3gp,3g2,mj2",
+        "format_long_name": "QuickTime / MOV",
+        "start_time": "0.000000",
+        "duration": "300.000000",
+        "size": "192000000",
+        "bit_rate": "5128000",
+        "probe_score": 100,
+        "tags": {
+            "major_brand": "isom",
+            "minor_version": "512",
+            "compatible_brands": "isomiso2avc1mp41",
+            "encoder": "Lavf58.20.100"
+        }
+    }
+}

tests/Jellyfin.MediaEncoding.Tests/Test Data/Probing/video_nanosecond_duration_bitrate.json

@@ -0,0 +1,49 @@
+{
+    "streams": [
+        {
+            "index": 0,
+            "codec_name": "h264",
+            "codec_long_name": "H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10",
+            "profile": "High",
+            "codec_type": "video",
+            "codec_tag_string": "[0][0][0][0]",
+            "codec_tag": "0x0000",
+            "width": 1920,
+            "height": 1080,
+            "coded_width": 1920,
+            "coded_height": 1080,
+            "has_b_frames": 2,
+            "pix_fmt": "yuv420p",
+            "level": 40,
+            "r_frame_rate": "24/1",
+            "avg_frame_rate": "24/1",
+            "time_base": "1/1000",
+            "start_pts": 0,
+            "start_time": "0.000000",
+            "disposition": {
+                "default": 1
+            },
+            "tags": {
+                "language": "eng",
+                "BPS-eng": "",
+                "DURATION-eng": "00:01:40.000000000",
+                "NUMBER_OF_FRAMES-eng": "2400",
+                "NUMBER_OF_BYTES-eng": "10000000"
+            }
+        }
+    ],
+    "format": {
+        "filename": "video_nanosecond_duration_bitrate.mkv",
+        "nb_streams": 1,
+        "nb_programs": 0,
+        "format_name": "matroska,webm",
+        "format_long_name": "Matroska / WebM",
+        "start_time": "0.000000",
+        "duration": "100.000000",
+        "size": "10001000",
+        "probe_score": 100,
+        "tags": {
+            "encoder": "libebml v1.4.2 + libmatroska v1.6.4"
+        }
+    }
+}

tests/Jellyfin.Server.Implementations.Tests/Item/AlternateVersionQueryTranslationTests.cs

@@ -0,0 +1,233 @@
+#pragma warning disable RS0030 // Do not use banned APIs: Guid == is required inside EF expression trees to mirror the production query shapes.
+
+using System;
+using System.Linq;
+using Jellyfin.Database.Implementations;
+using Jellyfin.Database.Implementations.Entities;
+using Jellyfin.Database.Implementations.Locking;
+using Jellyfin.Database.Providers.Sqlite;
+using Microsoft.Data.Sqlite;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging.Abstractions;
+using Xunit;
+
+namespace Jellyfin.Server.Implementations.Tests.Item;
+
+/// <summary>
+/// Verifies that the alternate-version-aware query shapes used by the resume filter
+/// (BaseItemRepository.TranslateQuery) and the DatePlayed ordering (OrderMapper) translate
+/// and evaluate correctly on the SQLite provider.
+/// </summary>
+public sealed class AlternateVersionQueryTranslationTests : IDisposable
+{
+    private readonly SqliteConnection _connection;
+    private readonly DbContextOptions<JellyfinDbContext> _dbOptions;
+
+    public AlternateVersionQueryTranslationTests()
+    {
+        _connection = new SqliteConnection("Data Source=:memory:");
+        _connection.Open();
+
+        _dbOptions = new DbContextOptionsBuilder<JellyfinDbContext>()
+            .UseSqlite(_connection)
+            .Options;
+
+        using var ctx = CreateDbContext();
+        ctx.Database.EnsureCreated();
+    }
+
+    [Fact]
+    public void ResumeFilter_VersionProgress_SurfacesPlayedVersion()
+    {
+        Guid userId, primaryId, versionId, otherId;
+
+        using (var ctx = CreateDbContext())
+        {
+            (userId, primaryId, versionId, otherId) = Seed(ctx);
+        }
+
+        using (var ctx = CreateDbContext())
+        {
+            var inProgress = ctx.UserData
+                .Where(ud => ud.UserId == userId && ud.PlaybackPositionTicks > 0);
+
+            // Scope to the seeded items; EnsureCreated also seeds a placeholder row.
+            var seededIds = new[] { primaryId, versionId, otherId };
+
+            // Mirrors the resumable=true filter in BaseItemRepository.TranslateQuery.
+            var inProgressIds = inProgress.Select(ud => ud.ItemId);
+            var resumable = ctx.BaseItems
+                .Where(e => seededIds.Contains(e.Id))
+                .Where(e => inProgressIds.Contains(e.Id))
+                .Where(e => !ctx.BaseItems
+                    .Where(s => s.Id != e.Id && (s.PrimaryVersionId ?? s.Id) == (e.PrimaryVersionId ?? e.Id))
+                    .Any(s =>
+                        inProgress.Where(su => su.ItemId == s.Id).Max(su => su.LastPlayedDate)
+                            > inProgress.Where(eu => eu.ItemId == e.Id).Max(eu => eu.LastPlayedDate)
+                        || (inProgress.Where(su => su.ItemId == s.Id).Max(su => su.LastPlayedDate)
+                                == inProgress.Where(eu => eu.ItemId == e.Id).Max(eu => eu.LastPlayedDate)
+                            && s.Id.CompareTo(e.Id) < 0)))
+                .Select(e => e.Id)
+                .ToList();
+
+            Assert.Equal([versionId], resumable);
+
+            // The not-resumable direction keeps primaries only.
+            var resumableMovieIds = inProgress
+                .Join(ctx.BaseItems, ud => ud.ItemId, bi => bi.Id, (ud, bi) => bi.PrimaryVersionId ?? bi.Id);
+            var notResumable = ctx.BaseItems
+                .Where(e => seededIds.Contains(e.Id) && e.PrimaryVersionId == null)
+                .Where(e => !resumableMovieIds.Contains(e.Id))
+                .Select(e => e.Id)
+                .ToList();
+
+            Assert.Equal([otherId], notResumable);
+        }
+    }
+
+    [Fact]
+    public void ResumeFilter_TiedLastPlayedDate_KeepsSingleVersion()
+    {
+        Guid userId, primaryId, versionAId, versionBId;
+
+        using (var ctx = CreateDbContext())
+        {
+            (userId, primaryId, versionAId, versionBId) = SeedTiedVersions(ctx);
+        }
+
+        using (var ctx = CreateDbContext())
+        {
+            var inProgress = ctx.UserData
+                .Where(ud => ud.UserId == userId && ud.PlaybackPositionTicks > 0);
+
+            var seededIds = new[] { primaryId, versionAId, versionBId };
+            var inProgressIds = inProgress.Select(ud => ud.ItemId);
+
+            // The exact production dedup, including the Guid.CompareTo tie-break. This asserts the
+            // expression translates on SQLite and that two versions sharing an identical LastPlayedDate
+            // collapse to a single row instead of double-listing the item in Continue Watching.
+            var resumable = ctx.BaseItems
+                .Where(e => seededIds.Contains(e.Id))
+                .Where(e => inProgressIds.Contains(e.Id))
+                .Where(e => !ctx.BaseItems
+                    .Where(s => s.Id != e.Id && (s.PrimaryVersionId ?? s.Id) == (e.PrimaryVersionId ?? e.Id))
+                    .Any(s =>
+                        inProgress.Where(su => su.ItemId == s.Id).Max(su => su.LastPlayedDate)
+                            > inProgress.Where(eu => eu.ItemId == e.Id).Max(eu => eu.LastPlayedDate)
+                        || (inProgress.Where(su => su.ItemId == s.Id).Max(su => su.LastPlayedDate)
+                                == inProgress.Where(eu => eu.ItemId == e.Id).Max(eu => eu.LastPlayedDate)
+                            && s.Id.CompareTo(e.Id) < 0)))
+                .Select(e => e.Id)
+                .ToList();
+
+            var survivor = Assert.Single(resumable);
+            Assert.Contains(survivor, new[] { versionAId, versionBId });
+        }
+    }
+
+    [Fact]
+    public void DatePlayedOrdering_VersionProgress_SortsPrimaryByVersionDate()
+    {
+        Guid userId, primaryId, otherId;
+
+        using (var ctx = CreateDbContext())
+        {
+            (userId, primaryId, _, otherId) = Seed(ctx);
+        }
+
+        using (var ctx = CreateDbContext())
+        {
+            // Scope to the seeded items; EnsureCreated also seeds a placeholder row.
+            var seededIds = new[] { primaryId, otherId };
+
+            // Mirrors the DatePlayed mapping in OrderMapper.
+            var ordered = ctx.BaseItems
+                .Where(e => seededIds.Contains(e.Id) && e.PrimaryVersionId == null)
+                .OrderByDescending(e => ctx.UserData
+                    .Where(w => w.UserId == userId && (w.ItemId == e.Id || w.Item!.PrimaryVersionId == e.Id))
+                    .Max(f => f.LastPlayedDate))
+                .Select(e => e.Id)
+                .ToList();
+
+            // The movie whose only progress is on its alternate version sorts before the unplayed one.
+            Assert.Equal([primaryId, otherId], ordered);
+        }
+    }
+
+    private static (Guid UserId, Guid PrimaryId, Guid VersionId, Guid OtherId) Seed(JellyfinDbContext ctx)
+    {
+        var user = new User("test", "auth-provider", "reset-provider");
+        ctx.Users.Add(user);
+
+        var primary = new BaseItemEntity { Id = Guid.NewGuid(), Type = "MediaBrowser.Controller.Entities.Movies.Movie" };
+        var version = new BaseItemEntity { Id = Guid.NewGuid(), Type = "MediaBrowser.Controller.Entities.Movies.Movie", PrimaryVersionId = primary.Id };
+        var other = new BaseItemEntity { Id = Guid.NewGuid(), Type = "MediaBrowser.Controller.Entities.Movies.Movie" };
+        ctx.BaseItems.AddRange(primary, version, other);
+
+        // Progress only on the alternate version.
+        ctx.UserData.Add(new UserData
+        {
+            ItemId = version.Id,
+            Item = version,
+            UserId = user.Id,
+            User = user,
+            CustomDataKey = version.Id.ToString("N"),
+            PlaybackPositionTicks = 1000,
+            LastPlayedDate = new DateTime(2026, 1, 2, 0, 0, 0, DateTimeKind.Utc)
+        });
+
+        ctx.SaveChanges();
+        return (user.Id, primary.Id, version.Id, other.Id);
+    }
+
+    private static (Guid UserId, Guid PrimaryId, Guid VersionAId, Guid VersionBId) SeedTiedVersions(JellyfinDbContext ctx)
+    {
+        var user = new User("test", "auth-provider", "reset-provider");
+        ctx.Users.Add(user);
+
+        var primary = new BaseItemEntity { Id = Guid.NewGuid(), Type = "MediaBrowser.Controller.Entities.Movies.Movie" };
+        var versionA = new BaseItemEntity { Id = Guid.NewGuid(), Type = "MediaBrowser.Controller.Entities.Movies.Movie", PrimaryVersionId = primary.Id };
+        var versionB = new BaseItemEntity { Id = Guid.NewGuid(), Type = "MediaBrowser.Controller.Entities.Movies.Movie", PrimaryVersionId = primary.Id };
+        ctx.BaseItems.AddRange(primary, versionA, versionB);
+
+        // Both versions in progress with the exact same LastPlayedDate - the tie that a strict '>' cannot break.
+        var tied = new DateTime(2026, 1, 2, 0, 0, 0, DateTimeKind.Utc);
+        ctx.UserData.Add(new UserData
+        {
+            ItemId = versionA.Id,
+            Item = versionA,
+            UserId = user.Id,
+            User = user,
+            CustomDataKey = versionA.Id.ToString("N"),
+            PlaybackPositionTicks = 1000,
+            LastPlayedDate = tied
+        });
+        ctx.UserData.Add(new UserData
+        {
+            ItemId = versionB.Id,
+            Item = versionB,
+            UserId = user.Id,
+            User = user,
+            CustomDataKey = versionB.Id.ToString("N"),
+            PlaybackPositionTicks = 2000,
+            LastPlayedDate = tied
+        });
+
+        ctx.SaveChanges();
+        return (user.Id, primary.Id, versionA.Id, versionB.Id);
+    }
+
+    private JellyfinDbContext CreateDbContext()
+    {
+        return new JellyfinDbContext(
+            _dbOptions,
+            NullLogger<JellyfinDbContext>.Instance,
+            new SqliteDatabaseProvider(null!, NullLogger<SqliteDatabaseProvider>.Instance),
+            new NoLockBehavior(NullLogger<NoLockBehavior>.Instance));
+    }
+
+    public void Dispose()
+    {
+        _connection.Dispose();
+    }
+}

tests/Jellyfin.Server.Implementations.Tests/Item/BaseItemRepositoryGroupingTests.cs

@@ -0,0 +1,144 @@
+using System;
+using System.Linq;
+using Emby.Server.Implementations.Data;
+using Jellyfin.Database.Implementations;
+using Jellyfin.Database.Implementations.Entities;
+using Jellyfin.Database.Implementations.Locking;
+using Jellyfin.Database.Providers.Sqlite;
+using Jellyfin.Server.Implementations.Item;
+using MediaBrowser.Controller;
+using MediaBrowser.Controller.Configuration;
+using MediaBrowser.Controller.Entities;
+using MediaBrowser.Model.Configuration;
+using MediaBrowser.Model.Entities;
+using Microsoft.Data.Sqlite;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging.Abstractions;
+using Moq;
+using Xunit;
+using BaseItemKind = Jellyfin.Data.Enums.BaseItemKind;
+
+namespace Jellyfin.Server.Implementations.Tests.Item;
+
+public sealed class BaseItemRepositoryGroupingTests : IDisposable
+{
+    private readonly SqliteConnection _connection;
+    private readonly DbContextOptions<JellyfinDbContext> _dbOptions;
+    private readonly BaseItemRepository _repository;
+    private readonly string _movieTypeName;
+
+    public BaseItemRepositoryGroupingTests()
+    {
+        _connection = new SqliteConnection("Data Source=:memory:");
+        _connection.Open();
+
+        _dbOptions = new DbContextOptionsBuilder<JellyfinDbContext>()
+            .UseSqlite(_connection)
+            .Options;
+
+        using (var ctx = CreateDbContext())
+        {
+            ctx.Database.EnsureCreated();
+        }
+
+        var factory = new Mock<IDbContextFactory<JellyfinDbContext>>();
+        factory.Setup(f => f.CreateDbContext()).Returns(CreateDbContext);
+
+        var itemTypeLookup = new ItemTypeLookup();
+        _movieTypeName = itemTypeLookup.BaseItemKindNames[BaseItemKind.Movie];
+
+        var serverConfigurationManager = new Mock<IServerConfigurationManager>();
+        serverConfigurationManager.Setup(c => c.Configuration).Returns(new ServerConfiguration());
+
+        _repository = new BaseItemRepository(
+            factory.Object,
+            new Mock<IServerApplicationHost>().Object,
+            itemTypeLookup,
+            serverConfigurationManager.Object,
+            NullLogger<BaseItemRepository>.Instance);
+    }
+
+    public void Dispose()
+    {
+        _connection.Dispose();
+    }
+
+    [Fact]
+    public void GetItemList_VersionGroup_ReturnsPrimaryVersion()
+    {
+        // The alternate version sorts before the primary by id, so a plain Min(Id) per
+        // presentation key would wrongly pick the alternate as the group representative.
+        var primaryId = Guid.Parse("eeeeeeee-eeee-eeee-eeee-eeeeeeeeeeee");
+        var alternateId = Guid.Parse("11111111-1111-1111-1111-111111111111");
+        var presentationKey = primaryId.ToString("N");
+
+        using (var ctx = CreateDbContext())
+        {
+            ctx.BaseItems.Add(CreateMovieEntity(primaryId, "Movie", presentationKey, null));
+            ctx.BaseItems.Add(CreateMovieEntity(alternateId, "Movie - 1080p", presentationKey, primaryId));
+            ctx.SaveChanges();
+        }
+
+        var result = _repository.GetItemList(CreateQuery());
+
+        var item = Assert.Single(result);
+        Assert.Equal(primaryId, item.Id);
+    }
+
+    [Fact]
+    public void GetItemList_GroupWithoutPrimary_FallsBackToMinId()
+    {
+        var firstId = Guid.Parse("22222222-2222-2222-2222-222222222222");
+        var secondId = Guid.Parse("dddddddd-dddd-dddd-dddd-dddddddddddd");
+        var otherPrimaryId = Guid.Parse("cccccccc-cccc-cccc-cccc-cccccccccccc");
+        var presentationKey = otherPrimaryId.ToString("N");
+
+        using (var ctx = CreateDbContext())
+        {
+            ctx.BaseItems.Add(CreateMovieEntity(firstId, "Movie", presentationKey, otherPrimaryId));
+            ctx.BaseItems.Add(CreateMovieEntity(secondId, "Movie - 4K", presentationKey, otherPrimaryId));
+            ctx.SaveChanges();
+        }
+
+        var result = _repository.GetItemList(CreateQuery());
+
+        var item = Assert.Single(result);
+        Assert.Equal(firstId, item.Id);
+    }
+
+    private static InternalItemsQuery CreateQuery()
+    {
+        // IncludeOwnedItems keeps the alternate version rows in the query so the
+        // grouping collapse is what picks the group representative.
+        return new InternalItemsQuery(new Database.Implementations.Entities.User("test", "auth", "reset"))
+        {
+            IncludeItemTypes = [BaseItemKind.Movie],
+            IncludeOwnedItems = true
+        };
+    }
+
+    private BaseItemEntity CreateMovieEntity(Guid id, string name, string presentationKey, Guid? primaryVersionId)
+    {
+        return new BaseItemEntity
+        {
+            Id = id,
+            Type = _movieTypeName,
+            Name = name,
+            PresentationUniqueKey = presentationKey,
+            PrimaryVersionId = primaryVersionId,
+            MediaType = "Video",
+            IsMovie = true,
+            IsFolder = false,
+            IsVirtualItem = false
+        };
+    }
+
+    private JellyfinDbContext CreateDbContext()
+    {
+        return new JellyfinDbContext(
+            _dbOptions,
+            NullLogger<JellyfinDbContext>.Instance,
+            new SqliteDatabaseProvider(null!, NullLogger<SqliteDatabaseProvider>.Instance),
+            new NoLockBehavior(NullLogger<NoLockBehavior>.Instance));
+    }
+}

tests/Jellyfin.Server.Implementations.Tests/Library/MediaSourceManagerTests.cs

@@ -1,4 +1,6 @@
 using System;
+using System.Collections.Generic;
+using System.Linq;
 using AutoFixture;
 using AutoFixture.AutoMoq;
 using Castle.Components.DictionaryAdapter;
@@ -7,6 +9,8 @@ using Emby.Server.Implementations.Library;
 using Jellyfin.Database.Implementations.Entities;
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Library;
+using MediaBrowser.Controller.LiveTv;
+using MediaBrowser.Controller.MediaSegments;
 using MediaBrowser.Model.Dto;
 using MediaBrowser.Model.Entities;
 using MediaBrowser.Model.Globalization;
@@ -144,5 +148,111 @@ namespace Jellyfin.Server.Implementations.Tests.Library
             _mediaSourceManager.SetDefaultAudioAndSubtitleStreamIndices(_item, mediaInfo, _user);
             Assert.Equal(expectedIndex, mediaInfo.DefaultAudioStreamIndex);
         }
+
+        [Fact]
+        public void GetStaticMediaSources_PrimaryQueried_PopulatesPerVersionPositionsAndDefaultsToMostRecent()
+        {
+            var (primary, alt1, alt2) = SetupVersionGroup();
+            SetupUserDataBatch(new Dictionary<Guid, UserItemData>
+            {
+                [alt1.Id] = new UserItemData { Key = "alt1", PlaybackPositionTicks = 10, LastPlayedDate = new DateTime(2026, 1, 1, 0, 0, 0, DateTimeKind.Utc) },
+                [alt2.Id] = new UserItemData { Key = "alt2", PlaybackPositionTicks = 20, LastPlayedDate = new DateTime(2026, 1, 2, 0, 0, 0, DateTimeKind.Utc) }
+            });
+
+            var sources = _mediaSourceManager.GetStaticMediaSources(primary, false, _user);
+
+            // Each version carries its own resume point; the primary has none.
+            Assert.Equal((long?)10, sources.First(s => s.Id == alt1.Id.ToString("N")).PlaybackPositionTicks);
+            Assert.Equal((long?)20, sources.First(s => s.Id == alt2.Id.ToString("N")).PlaybackPositionTicks);
+            Assert.Null(sources.First(s => s.Id == primary.Id.ToString("N")).PlaybackPositionTicks);
+
+            // The most recently played version is the default source, so resuming plays the right file.
+            Assert.Equal(alt2.Id.ToString("N"), sources[0].Id);
+        }
+
+        [Fact]
+        public void GetStaticMediaSources_AlternateQueried_KeepsOwnSourceFirst()
+        {
+            var (primary, alt1, alt2) = SetupVersionGroup();
+            SetupUserDataBatch(new Dictionary<Guid, UserItemData>
+            {
+                [alt2.Id] = new UserItemData { Key = "alt2", PlaybackPositionTicks = 20, LastPlayedDate = new DateTime(2026, 1, 2, 0, 0, 0, DateTimeKind.Utc) }
+            });
+
+            var sources = _mediaSourceManager.GetStaticMediaSources(alt1, false, _user);
+
+            // An explicitly opened version keeps its own source first, even when a sibling was
+            // played more recently, but the sibling's resume point is still populated.
+            Assert.Equal(alt1.Id.ToString("N"), sources[0].Id);
+            Assert.Equal((long?)20, sources.First(s => s.Id == alt2.Id.ToString("N")).PlaybackPositionTicks);
+            Assert.Equal(3, sources.Count);
+        }
+
+        [Fact]
+        public void GetStaticMediaSources_NoProgress_KeepsQueriedItemFirst()
+        {
+            var (primary, _, _) = SetupVersionGroup();
+            SetupUserDataBatch([]);
+
+            var sources = _mediaSourceManager.GetStaticMediaSources(primary, false, _user);
+
+            Assert.Equal(primary.Id.ToString("N"), sources[0].Id);
+            Assert.All(sources, s => Assert.Null(s.PlaybackPositionTicks));
+        }
+
+        [Fact]
+        public void GetStaticMediaSources_NoUser_DoesNotTouchUserData()
+        {
+            var (primary, _, _) = SetupVersionGroup();
+
+            var sources = _mediaSourceManager.GetStaticMediaSources(primary, false);
+
+            Assert.Equal(primary.Id.ToString("N"), sources[0].Id);
+            _mockUserDataManager.Verify(x => x.GetUserDataBatch(It.IsAny<IReadOnlyList<BaseItem>>(), It.IsAny<User>()), Times.Never);
+        }
+
+        private void SetupUserDataBatch(Dictionary<Guid, UserItemData> userData)
+        {
+            _mockUserDataManager
+                .Setup(x => x.GetUserDataBatch(It.IsAny<IReadOnlyList<BaseItem>>(), It.IsAny<User>()))
+                .Returns((IReadOnlyList<BaseItem> items, User _) => items
+                    .Where(i => userData.ContainsKey(i.Id))
+                    .ToDictionary(i => i.Id, i => userData[i.Id]));
+        }
+
+        private static (Video Primary, Video Alt1, Video Alt2) SetupVersionGroup()
+        {
+            var primary = new Video { Id = Guid.NewGuid(), Path = "/Movies/Movie/Movie.mkv" };
+            var alt1 = new Video { Id = Guid.NewGuid(), Path = "/Movies/Movie/Movie - 1080p.mkv", PrimaryVersionId = primary.Id };
+            var alt2 = new Video { Id = Guid.NewGuid(), Path = "/Movies/Movie/Movie - 4K.mkv", PrimaryVersionId = primary.Id };
+
+            // BaseItem.GetMediaSources runs against the static service locators.
+            var mediaSourceManager = new Mock<IMediaSourceManager>();
+            mediaSourceManager.Setup(x => x.GetPathProtocol(It.IsAny<string>())).Returns(MediaProtocol.File);
+            mediaSourceManager.Setup(x => x.GetMediaStreams(It.IsAny<Guid>())).Returns(new List<MediaStream>());
+            mediaSourceManager.Setup(x => x.GetMediaAttachments(It.IsAny<Guid>())).Returns(new List<MediaAttachment>());
+
+            var segmentManager = new Mock<IMediaSegmentManager>();
+            segmentManager.Setup(x => x.IsTypeSupported(It.IsAny<BaseItem>())).Returns(false);
+
+            var libraryManager = new Mock<ILibraryManager>();
+            libraryManager.Setup(x => x.GetLinkedAlternateVersions(It.IsAny<Video>())).Returns(Array.Empty<Video>());
+            libraryManager.Setup(x => x.GetLocalAlternateVersionIds(primary)).Returns(new[] { alt1.Id, alt2.Id });
+            libraryManager.Setup(x => x.GetLocalAlternateVersionIds(alt1)).Returns(Array.Empty<Guid>());
+            libraryManager.Setup(x => x.GetLocalAlternateVersionIds(alt2)).Returns(Array.Empty<Guid>());
+            libraryManager.Setup(x => x.GetItemById(primary.Id)).Returns(primary);
+            libraryManager.Setup(x => x.GetItemById(alt1.Id)).Returns(alt1);
+            libraryManager.Setup(x => x.GetItemById(alt2.Id)).Returns(alt2);
+
+            var recordingsManager = new Mock<IRecordingsManager>();
+            recordingsManager.Setup(x => x.GetActiveRecordingInfo(It.IsAny<string>())).Returns((ActiveRecordingInfo?)null);
+
+            BaseItem.MediaSegmentManager = segmentManager.Object;
+            BaseItem.MediaSourceManager = mediaSourceManager.Object;
+            BaseItem.LibraryManager = libraryManager.Object;
+            Video.RecordingsManager = recordingsManager.Object;
+
+            return (primary, alt1, alt2);
+        }
     }
 }

tests/Jellyfin.Server.Implementations.Tests/Localization/LocalizationManagerTests.cs

@@ -344,6 +344,20 @@ namespace Jellyfin.Server.Implementations.Tests.Localization
             Assert.NotEqual("Default", translated);
         }
 
+        [Fact]
+        public void GetLocalizedString_WithBcp47NormalizationToUppercaseRegion_ReturnsTranslation()
+        {
+            var localizationManager = Setup(new ServerConfiguration
+            {
+                UICulture = "en-US"
+            });
+
+            // he-IL normalizes to the underscore resource he_IL. The resource lookup is case-sensitive,
+            // so the region casing has to be preserved or the file is not found and we fall back to en-US.
+            var translated = localizationManager.GetLocalizedString("Books", "he-IL");
+            Assert.Equal("ספרים", translated);
+        }
+
         [Fact]
         public void GetServerLocalizedString_UsesServerCulture()
         {

tests/Jellyfin.Server.Implementations.Tests/Updates/InstallationManagerTests.cs

@@ -109,5 +109,29 @@ namespace Jellyfin.Server.Implementations.Tests.Updates
             var ex = await Record.ExceptionAsync(() => _installationManager.InstallPackage(packageInfo, CancellationToken.None));
             Assert.Null(ex);
         }
+
+        [Theory]
+        [InlineData("../evil")]
+        [InlineData("..\\evil")]
+        [InlineData("../../escape_attempt")]
+        [InlineData("..")]
+        [InlineData(".")]
+        [InlineData("")]
+        [InlineData("   ")]
+        [InlineData("foo/bar")]
+        [InlineData("foo\\bar")]
+        [InlineData("/absolute")]
+        [InlineData("foo\0bar")]
+        public async Task InstallPackage_InvalidName_ThrowsInvalidDataException(string name)
+        {
+            var packageInfo = new InstallationInfo()
+            {
+                Name = name,
+                SourceUrl = "https://repo.jellyfin.org/releases/plugin/empty/empty.zip",
+                Checksum = "11b5b2f1a9ebc4f66d6ef19018543361"
+            };
+
+            await Assert.ThrowsAsync<InvalidDataException>(() => _installationManager.InstallPackage(packageInfo, CancellationToken.None));
+        }
     }
 }

tests/Jellyfin.Server.Integration.Tests/Controllers/UserControllerTests.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Globalization;
-using System.Linq;
 using System.Net;
 using System.Net.Http;
 using System.Net.Http.Json;
@@ -164,5 +163,33 @@ namespace Jellyfin.Server.Integration.Tests.Controllers
             using var response = await UpdateUserPassword(client, _testUserId, createRequest);
             Assert.Equal(HttpStatusCode.NoContent, response.StatusCode);
         }
+
+        [Fact]
+        [Priority(2)]
+        public async Task UpdateUser_UsernameCaseDifference_Success()
+        {
+            var client = _factory.CreateClient();
+
+            client.DefaultRequestHeaders.AddAuthHeader(_accessToken!);
+
+            using var response = await client.GetAsync("Users/" + _testUserId, TestContext.Current.CancellationToken);
+            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+            var userDto = await response.Content.ReadFromJsonAsync<UserDto>(JsonDefaults.Options, TestContext.Current.CancellationToken);
+            Assert.NotNull(userDto);
+
+            userDto.Name = userDto.Name.ToLowerInvariant();
+
+            using var response2 = await client.PostAsJsonAsync($"Users?userId={_testUserId}", userDto, _jsonOptions, TestContext.Current.CancellationToken);
+            Assert.Equal(HttpStatusCode.NoContent, response2.StatusCode);
+
+            using var response3 = await client.GetAsync("Users/" + _testUserId, TestContext.Current.CancellationToken);
+            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
+            var newUserDto = await response3.Content.ReadFromJsonAsync<UserDto>(JsonDefaults.Options, TestContext.Current.CancellationToken);
+            Assert.NotNull(newUserDto);
+            Assert.Equal(userDto.Name, newUserDto.Name);
+
+            // Sanity check, make sure we're testing something
+            Assert.NotEqual(TestUsername, userDto.Name);
+        }
     }
 }

tests/Jellyfin.Server.Integration.Tests/SyncPlayLostWebSocketTests.cs

@@ -0,0 +1,140 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using System.Net;
+using System.Net.Http;
+using System.Net.Http.Json;
+using System.Net.WebSockets;
+using System.Reflection;
+using System.Text.Json;
+using System.Threading;
+using System.Threading.Tasks;
+using Emby.Server.Implementations.Session;
+using Jellyfin.Api.Models.SyncPlayDtos;
+using Jellyfin.Extensions.Json;
+using MediaBrowser.Controller.Net;
+using Microsoft.Extensions.DependencyInjection;
+using Xunit;
+
+namespace Jellyfin.Server.Integration.Tests;
+
+public sealed class SyncPlayLostWebSocketTests : IClassFixture<JellyfinApplicationFactory>
+{
+    private readonly JellyfinApplicationFactory _factory;
+
+    public SyncPlayLostWebSocketTests(JellyfinApplicationFactory factory)
+    {
+        _factory = factory;
+    }
+
+    [Fact]
+    public async Task LostWebSocket_EndsSession_And_RemovesEmptySyncPlayGroup()
+    {
+        var cancellationToken = TestContext.Current.CancellationToken;
+        var client = _factory.CreateClient();
+        var accessToken = await AuthHelper.CompleteStartupAsync(client);
+        client.DefaultRequestHeaders.AddAuthHeader(accessToken);
+
+        var wsClient = _factory.Server.CreateWebSocketClient();
+        wsClient.ConfigureRequest = request =>
+            request.Headers.Authorization = AuthHelper.DummyAuthHeader + $", Token={accessToken}";
+
+        var webSocket = await wsClient.ConnectAsync(
+            new UriBuilder(_factory.Server.BaseAddress)
+            {
+                Scheme = "ws",
+                Path = "websocket"
+            }.Uri,
+            cancellationToken);
+
+        _ = DrainAsync(webSocket, cancellationToken);
+
+        var watched = await WaitForWatchedWebSocketsAsync(TimeSpan.FromSeconds(10), cancellationToken);
+        var connection = Assert.Single(watched);
+
+        using var createResponse = await client.PostAsync(
+            "SyncPlay/New",
+            JsonContent.Create(new NewGroupRequestDto { GroupName = "ZombieGroupRepro" }, options: JsonDefaults.Options),
+            cancellationToken);
+        Assert.Equal(HttpStatusCode.OK, createResponse.StatusCode);
+        Assert.Equal(1, await WaitForGroupCountAsync(client, 1, TimeSpan.FromSeconds(10), cancellationToken));
+
+        connection.LastKeepAliveDate = DateTime.UtcNow - TimeSpan.FromSeconds(180);
+
+        var groupCount = await WaitForGroupCountAsync(client, 0, TimeSpan.FromSeconds(45), cancellationToken);
+        Assert.True(
+            groupCount == 0,
+            $"SyncPlay group still listed {groupCount} group(s) after the WebSocket was lost: "
+            + "the keep-alive watchdog removed the socket from its watchlist without closing "
+            + "the session, leaving a zombie participant in the group (SessionWebSocketListener).");
+    }
+
+    private static async Task DrainAsync(WebSocket webSocket, CancellationToken cancellationToken)
+    {
+        var buffer = new byte[4096];
+        try
+        {
+            while (webSocket.State == WebSocketState.Open)
+            {
+                await webSocket.ReceiveAsync(buffer, cancellationToken);
+            }
+        }
+        catch
+        {
+            // The server tears the connection down once the watchdog gives up on it.
+        }
+    }
+
+    private async Task<IReadOnlyList<IWebSocketConnection>> WaitForWatchedWebSocketsAsync(TimeSpan timeout, CancellationToken cancellationToken)
+    {
+        var listener = _factory.Services.GetRequiredService<IEnumerable<IWebSocketListener>>()
+            .OfType<SessionWebSocketListener>()
+            .Single();
+        var watchlistField = typeof(SessionWebSocketListener)
+            .GetField("_webSockets", BindingFlags.NonPublic | BindingFlags.Instance);
+        Assert.NotNull(watchlistField);
+        var watchlist = (IEnumerable<IWebSocketConnection>)watchlistField.GetValue(listener)!;
+
+        var stopwatch = Stopwatch.StartNew();
+        while (true)
+        {
+            try
+            {
+                var snapshot = watchlist.ToArray();
+                if (snapshot.Length > 0 || stopwatch.Elapsed >= timeout)
+                {
+                    return snapshot;
+                }
+            }
+            catch (InvalidOperationException)
+            {
+                // The watchdog mutated the set during enumeration; retry.
+            }
+
+            await Task.Delay(100, cancellationToken);
+        }
+    }
+
+    private static async Task<int> WaitForGroupCountAsync(HttpClient client, int expected, TimeSpan timeout, CancellationToken cancellationToken)
+    {
+        var stopwatch = Stopwatch.StartNew();
+        var count = -1;
+        while (stopwatch.Elapsed < timeout)
+        {
+            using var response = await client.GetAsync("SyncPlay/List", cancellationToken);
+            response.EnsureSuccessStatusCode();
+            await using var stream = await response.Content.ReadAsStreamAsync(cancellationToken);
+            using var document = await JsonDocument.ParseAsync(stream, cancellationToken: cancellationToken);
+            count = document.RootElement.GetArrayLength();
+            if (count == expected)
+            {
+                return count;
+            }
+
+            await Task.Delay(500, cancellationToken);
+        }
+
+        return count;
+    }
+}