"Missing BIOS" error (e.g., neogeo.zip). → Solution: Place required BIOS files in your roms folder alongside game zips. For Neo Geo, you need neogeo.zip . For CPS1/CPS2, no extra BIOS is needed.

Audio is crackly or slow. → Solution: In RetroArch, go to Quick Menu → Options → Audio → Audio Resampler , try "sinc" or "hermite". Also check that your refresh rate matches (60Hz for most arcades).

Check the official FBNeo GitHub or the RetroArch forums – but remember, sharing copyrighted roms is not allowed, so focus on tools, DAT files, and public domain games.