: FBNeo requires specific romsets that match its current version (e.g., FBNeo v1.0.0.x). Using old MAME or FB Alpha sets often leads to "unknown" errors because filenames or internal checksums have changed. Scanning Issues in RetroArch
CPS-3 emulation is notoriously strict. If you get the error: romset is unknown fbneo fixed
When you scan your library, the emulator checks the CRC (Cyclic Redundancy Check) of every file. If even one byte is different from the official database, the ROM won't load. : FBNeo requires specific romsets that match its