Thank you for the quick reply! It's just the empty Neo Geo list. I've got the settings configured the way you describe already. I did a bit more research. The first line below from my old gamelist.txt works, but the second one from my newest updated gamelist.txt doesn't. Perhaps this is related to the Neo Geo multi-slot changes in Mame .154? I tried renaming "neogeo_noslot.c" to "neogeo.c" in the new file and it made no difference. 2020bbh|2020 Super Baseball|SNK|1991|True|Sports / Baseball|True|H|320|224|2020bb||18[-LF-]173[-LF-]224[-LF-]233[-LF-]362[-LF-]228[-LF-]227[-LF-]429[-LF-]464[-LF-]473[-LF-]519[-LF-]3237[-LF-]609[-LF-]2845[-LF-]820[-LF-]745[-LF-]768[-LF-]870[-LF-]858[-LF-]884[-LF-]983[-LF-]985[-LF-]1153[-LF-]1152[-LF-]1267[-LF-]1372[-LF-]57[-LF-]3132[-LF-]1501[-LF-]1633[-LF-]1912[-LF-]226[-LF-]229[-LF-]2856[-LF-]2076[-LF-]3439[-LF-]2320[-LF-]1834[-LF-]2741[-LF-]2822[-LF-]2890[-LF-]2961[-LF-]2962[-LF-]2964[-LF-]2966[-LF-]2967[-LF-]2968[-LF-]2969[-LF-]2970[-LF-]2971[-LF-]3238[-LF-]2145[-LF-]2131[-LF-]3399[-LF-]3441[-LF-]3563[-LF-]3584[-LF-]3582|2P sim|0|False|False|joy8way||neogeo.c 2020bbh|2020 Super Baseball|SNK|1991|True|Sports / Baseball|True|H|320|224|2020bb||18[-LF-]173[-LF-]224[-LF-]235[-LF-]378[-LF-]228[-LF-]227[-LF-]447[-LF-]483[-LF-]492[-LF-]538[-LF-]3297[-LF-]629[-LF-]2906[-LF-]854[-LF-]777[-LF-]801[-LF-]905[-LF-]893[-LF-]920[-LF-]1021[-LF-]1023[-LF-]1193[-LF-]1192[-LF-]1308[-LF-]1420[-LF-]55[-LF-]3194[-LF-]1550[-LF-]1686[-LF-]1968[-LF-]226[-LF-]229[-LF-]2917[-LF-]2130[-LF-]3506[-LF-]2377[-LF-]1886[-LF-]2802[-LF-]2883[-LF-]2952[-LF-]3021[-LF-]3022[-LF-]3024[-LF-]3026[-LF-]3027[-LF-]3028[-LF-]3029[-LF-]3030[-LF-]3031[-LF-]3298[-LF-]2198[-LF-]2184[-LF-]3466[-LF-]3508[-LF-]3632[-LF-]3653[-LF-]3651|2P sim|1000|False|False|joy8way||neogeo_noslot.c For clarity, all roms and the BIOS are verified with clrMAMEPro using the same mame executable as I'm using in GameEx.