Before diving into the unknown ROMset issue, let's quickly cover what a ROMset is. A ROMset, short for "ROM collection," refers to a set of files extracted from a game's original read-only memory (ROM) chips. These files contain the game's code and data, which can be used by an emulator to run the game on a different platform. In essence, a ROMset is the digital equivalent of the original game cartridge or arcade board.
Incorrect file naming is rarely the cause of a "Romset is unknown" error. FBNeo identifies games by the data inside the ZIP file, not the name of the ZIP file itself. If you rename pacman.zip to burger.zip , FBNeo will still identify it as Pac-Man. If you get this error, the data inside the file does not match what FBNeo expects for that game. romset is unknown fbneo