I have the same issue, I have reinstalled both Launchbox premium and Retroarch multiple times and still have the same issue. Retroarch will open the Roms fine but, when I use Launchbox to open a game through Retroarch, I see the image of the game box from Retroarch then a black screen. The games will not open using La4unchbox and Retroarch. Launchbox will open Retroarch when testing and shows that it is recognized in the setting menu but will not open/launch the game successfully.