Guessing he's having the standard "JoiPlay doesn't work" problem, but hoping you'll fix someone else's program. RenPy is just an addon needed for JoiPlay to run the game after all.
You must mean JoiPlay, RenPy is just an addon that lets you run the game. Ask JoiPlay's forums, they sometimes release broken versions and it's up to them to fix their program, not a random indie game dev. Best we can offer is to downgrade your JoiPlay to a working version, as this fellow offered.
