Stop the Jellyfin Docker
Open the Unraid console
Navigate to /mnt/user/appdata/jellyfin/data/data

Verify the correct database with an integrity check:

sqlite3 library.db "PRAGMA integrity_check"

Run the following commands:

sqlite3 library.db ".recover" | sqlite3 new.db
mv library.db ./library.db.OLD
mv new.db ./library.db
chown nobody:users library.db
chmod 777 library.db