Homepage › Forums › RetroPie Project › Everything else related to the RetroPie Project › Advance MAME › Reply To: Advance MAME
Have you checked your romset with the relevant dat file?
http://smartretro.co.uk/forums/viewtopic.php?f=3&t=68
There is a guide to verify them here:
https://github.com/retropie/RetroPie-Setup/wiki/Managing-ROMs