Jellyfin Authentication issue - request.App is null

Support
1

Issue description:

Using Jellyfin 10.11.5
and Symfonium 13.7.0 (127660) on Android I get the following error whenever I try to connect to the server:

[2026-01-18 10:34:22.041 -08:00] [INF] [114] Jellyfin.Api.Auth.CustomAuthenticationHandler: AuthenticationScheme: "CustomAuthentication" was challenged.
[2026-01-18 10:34:22.100 -08:00] [ERR] [12] Jellyfin.Api.Middleware.ExceptionMiddleware: Error processing request. URL "POST" "/Users/AuthenticateByName".
System.ArgumentNullException: Value cannot be null. (Parameter 'request.App')
   at System.ArgumentNullException.Throw(String paramName)
   at System.ArgumentNullException.ThrowIfNull(Object argument, String paramName)
   at System.ArgumentException.ThrowNullOrEmptyException(String argument, String paramName)
   at Emby.Server.Implementations.Session.SessionManager.AuthenticateNewSessionInternal(AuthenticationRequest request, Boolean enforcePassword)
   at Jellyfin.Api.Controllers.UserController.AuthenticateUserByName(AuthenticateUserByName request)
   at lambda_method463320(Closure, Object)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.AwaitableObjectResultExecutor.Execute(ActionContext actionContext, IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Awaited|12_0(ControllerActionInvoker invoker, ValueTask`1 actionResultValueTask)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeInnerFilterAsync()

I know there was some sort of Auth change in 13.7, it’s possible that’s now broken. The error suggests that Symfonium needs to send a value in request.App ?

The only similar issue I found on the forum had a user on 10.12 needing to enable EnableLegacyAuthorization , but I’ve confirmed that’s already enabled on my 10.11.

Logs:

Upload description: jedi.jesse - Jellyfin Authentication

Additional information:

 

 

Reproduction steps:

 
Open Symfonium
Tap Source Filter
see that Jellyfin shows “Authentication Error”
No amount of re-typing the password can ever get it to connect (see logs)
 

Media provider:

Jellyfin

Screenshots:

     

2

You did not upload Symfonium logs.

You might also want to add the provider again and see if it works.

3

Ah, I thought the Jellyfin logs would be helpful, as they show the error, so I uploaded those.
I’ve uploaded the Symfonium logs now.
I’ll go ahead and remove and re-add the media provider, if that’s the solution. I was hoping to not have to resync the entire library (which I keep offline), but I guess that’s not actually so bad.

4

Don’t remove.
Add again first, sync then remove to keep offline cache.

And I need logs that reproduce the issue not empty ones :wink:

5

I have no way of knowing what’s in the Symfonium logs when I send them. Uploading those is a very opaque process, but I did verify that I saw the authentication error in the app before sending and I’m pretty sure debug mode was on, so I don’t know why the app generated empty logs.

I followed your suggestion of re-adding the provider and it worked, so now I can’t reproduce it.