I’m possibly having the same issue.
Downloaded & installed retroarch today. Updated\downloaded PlayStation core Scanned directory where I had my home made ROMs (I mean i ripped Digimon World disc myself) Tried to play game but ‘failed to load content’ Tried adding a bios file and pointing retroarch to it in the bios settings option. Still no dice.
Tried the above on both win10 & android. Tried multiple ROMs. Any advice would be much appreciated and sorry for hijacking this thread, hopefully the cause is the same and fixable:)