SOLVED: Jellyfin client - connect button greyed out

[DaviAMSilva]

For any Linux user that, like me, finds this thread trying to solve the same problem with the Linux version installed via flapak:

The way I solved it was by going to the directory "~/.var/app/" and finding the folder named "com.github.iwalton3.jellyfin-media-player".
I just renamed the folder to something else and launched the app. It recreated the folder and the button began working again.
Only detail is that any client configurations are lost but that is probably a small thing for most people.