Funny to see this today. I had moved a repo from an old Mac laptop to linux months ago, and git couldn’t find the ref to HEAD, because HEAD was pointing to the case insensitive branch name, and it didn’t match the case of the branch. Manually edited HEAD to the correct case to fix it. I should probably recreate the repo for good measure…

Good to hear. I think jellyfin could be improved so that it doesn’t completely clear migrations.xml every time a new migration is applied when it starts up (switch from a Create to an OpenOrCreate on the file). Although a low disk situation can be difficult for software to deal with typically anyway.

Can you check your config folder (seems like it’s /etc/jellyfin for you) for migrations.xml and system.xml? I’m guessing if you were low on disk, jellyfin tried to write to them, but couldn’t, so it left empty files which it can’t now read from.