Can you run MAME Plus outside of GameEx? Your config is set to use GameEx integrated MAME support, as long as your paths are correct all you need to do is point to your executable. It appears you have done this. Double check your paths in MAME, and in Advance MAME Settings (not to be confused with AdvanceMAME) Unless I overlooked something, which is entirely possible as your config is quite involved, I don't see MAME configured as a Emulator (which by-passes integrated support) so there is no command line.