Jellyseerr Is Unable to Connect to Jellyfin Server [ Something went wrong while authenticating with the Jellyfin server: Request failed with status code 400]

Insight & Feedback
1

I am running into an issue where I can’t connect Jellyseerr (2.7.3) to Jellyfin Server (12.0). I had my server turned off for a couple months cause I kept running into issues when setting up my Jellyfin Server. After coming back I update my ZimaOS (v1.7.1) along side other apps.

When trying to test media download via Jellyseerr I was unable to log in and getting the message “Something went wrong while trying to sign in.” and looking into the logs I see the following message “[e[31merrore[39m][Jellyfin API]: Something went wrong while authenticating with the Jellyfin server: Request failed with status code 400”.

Looking into it the status code it looks like it is because Jellyseerr can’t connect to the server, but can still see it?

What I’ve done so far is make sure that both Jellyseerr and Jellyfin are on the same Network Type
Created a new private key for gluetun
Made sure that gluetun was turned on in docker
Made sure Cloudflare tunnels are up
Even restarting, Jellyseerr, Jellyfin, and the home server itself.
Uninstalled Jellyseerr (and even removing the files from the directory)

Looking to see if anyone else has run into this issue or if anyone has a solution.

2

Had the same problem,
Jellyfin updates (like 10.12+) may disable legacy authorization by default, which breaks Jellyseerr logins. You can check your Jellyfin system.xml file and ensure EnableLegacyAuthorization is set to true. [1]
Did this and it allowed my Jellyseerr to at least get through setup

3

I gave that a try just now and it didn’t work.
I starting looking through Jellyfin’s log when attempting to connect and found this error message
[ERR] [13] Jellyfin.Api.Middleware.ExceptionMiddleware: Error processing request. URL POST /Users/AuthenticateByName.

It seems like its related to permissions for Jellyfin accornding to this form post
The logs shared there are very similar to what I get, but the solutions appears to be for Jellyfin to Run as Administrator