If a game won't load, make sure you have the parent ZIP file in the same folder.
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?
Most people encounter this issue while using the . RetroArch is particularly sensitive to ROM versions. romset is unknown fbneo fixed
Many "unknown" errors are actually caused by missing system files. Ensure you have the latest versions of: neogeo.zip (for SNK games) cpzn2.zip (for Capcom ZN2 games) pgm.zip (for PolyGame Master games) Why "Fixed" Sets Matter for RetroArch Users
Use a manager to ensure your files aren't corrupted or old dumps. If a game won't load, make sure you
These require a "Parent" ROM to function. If you have a "Clone" (like a Japanese version of a game) but not the Parent (the World version), it will appear as unknown or broken. 3. Update Your BIOS Files
Run a "Scan" and "Fix." The software will rename files, move them into the correct ZIPs, and tell you exactly which files you are missing. 2. Seek "FBNeo Fixed" Sets Which specific game is giving you the "Unknown" error
FBNeo is updated frequently. If the emulator expects a specific file within a ZIP (like a sound chip dump) and it isn't there, it marks the set as "unknown."