There seems to be a problem with the zip library used in RetroArch in the most recent version of RetroPie. I have all of my roms zipped, and every time I try to run a gameboy, gameboy color, genesis/megadrive, nes or snes game, the extraction fails. I can’t find a log file, but I can see the message “zip extraction failed on line xxx” when it tries to launch a game. I don’t have any problem with GBA or Master System games.