While FBNeo is a fork of MAME, their ROM requirements have diverged over the years. MAME prioritizes preservation of every chip on a PCB, including security chips and decapped CPUs. FBNeo prioritizes playability and often uses "hacked" or simplified decryption methods. Consequently, a modern MAME romset will frequently be "unknown" to FBNeo, and vice versa.
Alex’s phone buzzed. A message from his friend, Mira. fbneo romset unknown
It is important to address why this error persists. Arcade emulation exists in a legal gray area. FBNeo developers cannot legally distribute ROMs. They can only distribute the and the DAT file (a recipe). Consequently, the internet is flooded with ROMs from 2005, 2010, and 2020, all conflicting. While FBNeo is a fork of MAME, their