Guys, I was having a similar problem - where retroarch would not work when launching a game using launchbox.
My problem was the following:
I imported my Super Nintendo games using a custom plataform name. I've chosen to import Snes games using the name "Nintendo - SNES", so all Nintendo plataforms would be next to each other. I've selected the scrap option to scrap the games as Super Nintendo Entertaiment System and all the games were imported successfully.
But since retroarch will not automatically add custom plataform names to its associated plataforms options, all I had to do
