So, I have every other system I've tried so far (Atari 2600, 5200, NES, and SNES) working fine, but I cannot for the life of me figure out how to get my beloved Metal Slug to work. It will either load and say 'No Content', immediately close Retroarch, or crash Retroarch with a 'sending this issue to Microsoft' popup. I am absolutely clueless when it comes to this piece of software. I need a step by step guide- like you were explaining how to get it working to your grandmother. Here is what I have done so far: Gotten the game files from Emuparadise Installed all of the different versions of Arcade cores. Tried them all on Metal Slug 2 Downloaded the MAME and MESS bios files from Emuparadise when I read that the BIOS files needed to be in the same directory as the games. Extracted those files (.rar for the MAME files and.zip for MESS) to my Retroarch folder It still isn't working, and I am out of ideas.