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.

I can provide a step-by-step guide tailored to your specific setup!

When in doubt, use "Non-Merged" sets to avoid dependency issues.

If you'd like to get your library fully operational, I can help you further. Let me know: Are you using or the Standalone FBNeo ? Which specific game is giving you the "Unknown" error?