The biggest mistake casual users make is assuming MAME ROMs work in FBNeo. They often do, but not always. FBNeo has forked its own path.
Are you seeing this error on or just one specific title? romset is unknown fbneo fixed
: The clone game zip file only contains the differences from the parent game. You must have the parent zip file in the same folder, or the clone will give an error. The biggest mistake casual users make is assuming
: Ensure it is a .zip or .7z file and not unzipped into a folder. romset is unknown fbneo fixed
If you have a large library showing this error, auditing it manually is impossible. You can use a tool like or RomCenter to automatically fix your files.