Did permissions change or is a drive not mounted? It sounds like after the install it did a library scan and didn't find anything. Do you have a backup of your jellyfin data directory?
Jellyfin 10.10.3 (Docker)
Ubuntu 24.04 LTS
Intel i3 12100
Intel Arc A380
OS drive - SK Hynix P41 1TB
Storage
3x WD Red Pro 6TB CMR in RAIDZ1 (JF Library)