Fbneo Romset Unknown -

If you decide to update your RetroArch cores or standalone FBNeo build, prepare to update your ROM collection shortly after to prevent your library from becoming "unknown."

Some users report that the emulator works perfectly when launched directly through RetroArch but fails when the same ROM is launched through a frontend like LaunchBox. This often occurs because the frontend is configured to ZIP files before passing them to the emulator. Arcade ROMs must remain zipped—extracting them breaks the file structure FBNeo expects. fbneo romset unknown

FBNeo is actively developed and frequently updates its ROM definitions to match current MAME standards. If your ROM set is from an older version of FBNeo or an outdated MAME collection, the core won't recognize it. If you decide to update your RetroArch cores