[Tranga broke]: Running the same search term twice causes internal server error.

[clovisNyu]

What is broken?

On the /v2/Search/{MangaConnectorName}/{Query}, if I use the same query twice, the second call will return a 500 Internal Server Error. I also tried running /v2/Maintenance/CleanupNoDownloadManga, but the problem doesn't go away. The logs seem to indicate a conflicting entry in the database.

Log-output

tranga-api  | 2025-12-28 23:20:55,393 [82] DEBUG API.Tranga - Adding Manga to Context: Manga-b897bad184f820ceb5a8d93c09084547 Bocchi the Rock!
tranga-api  | 2025-12-28 23:20:56,987 [88] DEBUG API.Tranga - Merging with existing Manga: Manga-b897bad184f820ceb5a8d93c09084547 Bocchi the Rock!
tranga-api  | fail: Microsoft.AspNetCore.Server.Kestrel[13]
tranga-api  |       Connection id "0HNI5533EGLF5", Request id "0HNI5533EGLF5:00000005": An unhandled exception was thrown by the application.
tranga-api  |       System.AggregateException: One or more errors occurred. (The instance of entity type 'MangaConnectorId<Manga>' cannot be tracked because another instance with the same key value for {'Key'} is already being tracked. When attaching existing entities, ensure that only one entity instance with a given key value is attached. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see the conflicting key values.)
tranga-api  |        ---> System.InvalidOperationException: The instance of entity type 'MangaConnectorId<Manga>' cannot be tracked because another instance with the same key value for {'Key'} is already being tracked. When attaching existing entities, ensure that only one entity instance with a given key value is attached. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see the conflicting key values.
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.IdentityMap`1.ThrowIdentityConflict(InternalEntityEntry entry)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.IdentityMap`1.Add(TKey key, InternalEntityEntry entry, Boolean updateDuplicate)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.StartTracking(InternalEntityEntry entry)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.InternalEntityEntry.SetEntityState(EntityState oldState, EntityState newState, Boolean acceptChanges, Boolean modifyProperties)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.EntityGraphAttacher.PaintAction(EntityEntryGraphNode`1 node)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.EntityEntryGraphIterator.TraverseGraph[TState](EntityEntryGraphNode`1 node, Func`2 handleNode)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.EntityGraphAttacher.AttachGraph(InternalEntityEntry rootEntry, EntityState targetState, EntityState storeGeneratedWithKeySetTargetState, Boolean forceStateWhenUnknownKey)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.NavigationFixer.NavigationCollectionChanged(InternalEntityEntry entry, INavigationBase navigationBase, IEnumerable`1 added, IEnumerable`1 removed)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.ChangeDetector.DetectNavigationChange(InternalEntityEntry entry, INavigationBase navigationBase)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.ChangeDetector.LocalDetectChanges(InternalEntityEntry entry)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.ChangeDetector.DetectChanges(IStateManager stateManager)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.ChangeTracker.Entries()
tranga-api  |          at API.Schema.TrangaBaseContext`1.Sync(CancellationToken token, Type trigger, String reason)
tranga-api  |          at API.Tranga.AddMangaToContext(MangaContext context, Manga addManga, MangaConnectorId`1 addMcId, CancellationToken token) in /src/API/Tranga.cs:line 237
tranga-api  |          at API.Tranga.AddMangaToContext(MangaContext context, ValueTuple`2 addManga, CancellationToken token) in /src/API/Tranga.cs:line 199
tranga-api  |          --- End of inner exception stack trace ---
tranga-api  |          at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
tranga-api  |          at System.Linq.Enumerable.CastIterator[TResult](IEnumerable source)+MoveNext()
tranga-api  |          at System.Linq.Enumerable.IEnumerableSelectIterator`2.ToList()
tranga-api  |          at API.Controllers.SearchController.SearchManga(String MangaConnectorName, String Query) in /src/API/Controllers/SearchController.cs:line 51
tranga-api  |          at lambda_method806(Closure, Object, Object[])
tranga-api  |          at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.SyncObjectResultExecutor.Execute(ActionContext actionContext, IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
tranga-api  |          at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeActionMethodAsync()
tranga-api  |          at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
tranga-api  |          at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeNextActionFilterAsync()
tranga-api  |       --- End of stack trace from previous location ---
tranga-api  |          at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
tranga-api  |          at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
tranga-api  |          at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeInnerFilterAsync()
tranga-api  |       --- End of stack trace from previous location ---
tranga-api  |          at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeFilterPipelineAsync>g__Awaited|20_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
tranga-api  |          at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
tranga-api  |          at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
tranga-api  |          at Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIMiddleware.Invoke(HttpContext httpContext)
tranga-api  |          at Swashbuckle.AspNetCore.Swagger.SwaggerMiddleware.Invoke(HttpContext httpContext, ISwaggerProvider swaggerProvider)
tranga-api  |          at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
tranga-api  |          at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
tranga-api  |          at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.ProcessRequests[TContext](IHttpApplication`1 application)
tranga-api  | 2025-12-28 23:20:58,923 [64] DEBUG API.Tranga - Starting StartNewChapterDownloadsWorker-uiap5i2v08shwrax4pkkeqa5m2qhwfmlm
tranga-api  | 2025-12-28 23:20:58,923 [64] DEBUG API.Workers.PeriodicWorkers.StartNewChapterDownloadsWorker - Checking StartNewChapterDownloadsWorker-uiap5i2v08shwrax4pkkeqa5m2qhwfmlm
tranga-api  | 2025-12-28 23:20:58,923 [64] INFO  API.Workers.PeriodicWorkers.StartNewChapterDownloadsWorker - Running StartNewChapterDownloadsWorker-uiap5i2v08shwrax4pkkeqa5m2qhwfmlm
tranga-api  | 2025-12-28 23:20:58,923 [64] DEBUG API.Workers.PeriodicWorkers.StartNewChapterDownloadsWorker - Checking for missing chapters...
tranga-api  | 2025-12-28 23:20:58,925 [64] DEBUG API.Workers.PeriodicWorkers.StartNewChapterDownloadsWorker - Found 0 missing chapters.
tranga-api  | 2025-12-28 23:20:58,925 [64] DEBUG API.Workers.PeriodicWorkers.StartNewChapterDownloadsWorker - 0 chapter not being downloaded
tranga-api  | 2025-12-28 23:20:58,925 [64] DEBUG API.Workers.PeriodicWorkers.StartNewChapterDownloadsWorker - 0 running download Workers. 9 available new download Workers.
tranga-api  | 2025-12-28 23:20:58,925 [64] INFO  API.Workers.PeriodicWorkers.StartNewChapterDownloadsWorker - Completed StartNewChapterDownloadsWorker-uiap5i2v08shwrax4pkkeqa5m2qhwfmlm
tranga-api  |   1.4159 ms
tranga-api  | 2025-12-28 23:20:58,925 [64] DEBUG API.Tranga - DefaultAfterWork StartNewChapterDownloadsWorker-uiap5i2v08shwrax4pkkeqa5m2qhwfmlm
tranga-api  | 2025-12-28 23:20:58,925 [64] DEBUG API.Tranga - Children done StartNewChapterDownloadsWorker-uiap5i2v08shwrax4pkkeqa5m2qhwfmlm
tranga-api  | 2025-12-28 23:20:58,925 [64] DEBUG API.Tranga - StartNewChapterDownloadsWorker-uiap5i2v08shwrax4pkkeqa5m2qhwfmlm created 0 new Workers.
tranga-api  | 2025-12-28 23:20:58,925 [64] DEBUG API.Tranga - Refreshing StartNewChapterDownloadsWorker-uiap5i2v08shwrax4pkkeqa5m2qhwfmlm
tranga-api  | 2025-12-28 23:20:58,925 [64] DEBUG API.Tranga - Waiting 00:01:00 for next run of StartNewChapterDownloadsWorker-uiap5i2v08shwrax4pkkeqa5m2qhwfmlm

Tranga version

tranga-api  | 2025-12-27 09:17:27,547 [1] INFO  Startup -
tranga-api  |
tranga-api  |  _______                                 v2
tranga-api  | |_     _|.----..---.-..-----..-----..---.-.
tranga-api  |   |   |  |   _||  _  ||     ||  _  ||  _  |
tranga-api  |   |___|  |__|  |___._||__|__||___  ||___._|
tranga-api  |                              |_____|
tranga-api  | --11/25/2025 21:07:51 for AnyCpu

Additional stuff

No response

[yacob841]

@C9Glax this was the issue I was experiencing and I fixed as part of the AsuraComic Pull, I believe it was the modifications to the Tranga.cs

[C9Glax]

What @yacob841 said. There is a problem with merging what already exists in the database with what we fetch from the website.

[clovisNyu]

Okay! Will wait for the AsuraComic pull to merge then! Thanks!

[C9Glax]

@clovisNyu The AsuraComic PR has been merged. Can you test if the behavior changed?

[clovisNyu]

Seems to work for search multiple times in a row, but once I configure a title to start tracking it stops working again. I'm assuming I have to fully delete some table to be able to update the table schema to fix the problem? If so, will need some time to note down the titles I'm tracking first before I make that change.

[yacob841]

I stopped experiencing the issue and I’m not experiencing what clovis is, so hopefully refreshing the db solves it

[clovisNyu]

Hi, unfortunately no, I completely deleted the database, but I still have the same issue. On a clean setup,

1. Search "bocchi".
2. Start downloading a few of the results.
3. Go to settings to use "Clean database" and "Clean actions".
4. Search "bocchi" again.
5. Internal Server Error

2026-01-07 22:04:32,327 [30] DEBUG Global - Got 129 results.
tranga-api  | 2026-01-07 22:04:32,327 [30] DEBUG API.Tranga - Adding Manga to Context: Manga-e96b62d09ef804c03238c26a65c89d60 Class no Bocchi Gyaru wo Omochikaeri Shite Seiso Kei Bijin ni Shiteyatta Hanash
tranga-api  | 2026-01-07 22:04:32,339 [69] DEBUG API.Tranga - Merging with existing Manga: Manga-e96b62d09ef804c03238c26a65c89d60 Class no Bocchi Gyaru wo Omochikaeri Shite Seiso Kei Bijin ni Shiteyatta Hanash
tranga-api  | fail: Microsoft.AspNetCore.Server.Kestrel[13]
tranga-api  |       Connection id "0HNIDT98BQVJ0", Request id "0HNIDT98BQVJ0:00000001": An unhandled exception was thrown by the application.
tranga-api  |       System.AggregateException: One or more errors occurred. (The instance of entity type 'MangaConnectorId<Manga>' cannot be tracked because another instance with the same key value for {'Key'} is already being tracked. When attaching existing entities, ensure that only one entity instance with a given key value is attached. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see the conflicting key values.)
tranga-api  |        ---> System.InvalidOperationException: The instance of entity type 'MangaConnectorId<Manga>' cannot be tracked because another instance with the same key value for {'Key'} is already being tracked. When attaching existing entities, ensure that only one entity instance with a given key value is attached. Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to see the conflicting key values.
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.IdentityMap`1.ThrowIdentityConflict(InternalEntityEntry entry)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.IdentityMap`1.Add(TKey key, InternalEntityEntry entry, Boolean updateDuplicate)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.StartTracking(InternalEntityEntry entry)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.InternalEntityEntry.SetEntityState(EntityState oldState, EntityState newState, Boolean acceptChanges, Boolean modifyProperties)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.InternalEntityEntry.SetEntityState(EntityState entityState, Boolean acceptChanges, Boolean modifyProperties, Nullable`1 forceStateWhenUnknownKey, Nullable`1 fallbackState)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.EntityGraphAttacher.PaintAction(EntityEntryGraphNode`1 node)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.EntityEntryGraphIterator.TraverseGraph[TState](EntityEntryGraphNode`1 node, Func`2 handleNode)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.EntityGraphAttacher.AttachGraph(InternalEntityEntry rootEntry, EntityState targetState, EntityState storeGeneratedWithKeySetTargetState, Boolean forceStateWhenUnknownKey)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.NavigationFixer.NavigationCollectionChanged(InternalEntityEntry entry, INavigationBase navigationBase, IEnumerable`1 added, IEnumerable`1 removed)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.ChangeDetector.DetectNavigationChange(InternalEntityEntry entry, INavigationBase navigationBase)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.ChangeDetector.LocalDetectChanges(InternalEntityEntry entry)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.ChangeDetector.DetectChanges(IStateManager stateManager)
tranga-api  |          at Microsoft.EntityFrameworkCore.ChangeTracking.ChangeTracker.Entries()
tranga-api  |          at API.Schema.TrangaBaseContext`1.Sync(CancellationToken token, Type trigger, String reason)
tranga-api  |          at API.Tranga.AddMangaToContext(MangaContext context, Manga addManga, MangaConnectorId`1 addMcId, CancellationToken token) in /src/API/Tranga.cs:line 237
tranga-api  |          at API.Tranga.AddMangaToContext(MangaContext context, ValueTuple`2 addManga, CancellationToken token) in /src/API/Tranga.cs:line 199
tranga-api  |          --- End of inner exception stack trace ---
tranga-api  |          at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
tranga-api  |          at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
tranga-api  |          at System.Threading.Tasks.Task`1.get_Result()
tranga-api  |          at API.Controllers.SearchController.<>c.<SearchManga>b__2_2(Task`1 t) in /src/API/Controllers/SearchController.cs:line 41
tranga-api  |          at System.Linq.Enumerable.IEnumerableWhereSelectIterator`2.MoveNext()
tranga-api  |          at System.Linq.Enumerable.CastIterator[TResult](IEnumerable source)+MoveNext()
tranga-api  |          at System.Linq.Enumerable.IEnumerableSelectIterator`2.ToList()
tranga-api  |          at API.Controllers.SearchController.SearchManga(String MangaConnectorName, String Query) in /src/API/Controllers/SearchController.cs:line 51
tranga-api  |          at lambda_method3071(Closure, Object, Object[])
tranga-api  |          at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.SyncObjectResultExecutor.Execute(ActionContext actionContext, IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
tranga-api  |          at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeActionMethodAsync()
tranga-api  |          at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
tranga-api  |          at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeNextActionFilterAsync()
tranga-api  |       --- End of stack trace from previous location ---
tranga-api  |          at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
tranga-api  |          at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
tranga-api  |          at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeInnerFilterAsync()
tranga-api  |       --- End of stack trace from previous location ---
tranga-api  |          at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeFilterPipelineAsync>g__Awaited|20_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
tranga-api  |          at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
tranga-api  |          at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
tranga-api  |          at Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIMiddleware.Invoke(HttpContext httpContext)
tranga-api  |          at Swashbuckle.AspNetCore.Swagger.SwaggerMiddleware.Invoke(HttpContext httpContext, ISwaggerProvider swaggerProvider)
tranga-api  |          at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
tranga-api  |          at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
tranga-api  |          at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.ProcessRequests[TContext](IHttpApplication`1 application)

One behavior that seems different is that now the first result of the search seems to populate on the main page, but "Clean database" can't seem to remove it anymore.

This is what my main page looks like after the steps I listed above. The third entry on the page "Class no Bocchi Gyaru..." is the title that caused the error in the logs. It also cannot be removed from my homepage via "Clean database".