Hmmm, that means there's something wrong with your RenPy SDK folder. I've literally used the zip I posted with folder modification changing RenPy_Saves to Wills747No, this one seems to work also on the new device. I installed the game, made a save and removed the game again. After I re-installed it the save was still there.
IMO delete it and set it up again.
Use the SDK with rapt included in the first post, you can also add the main.rpy file from my post above to the sdk/renpy folder if you like. It shouldn't be needed but I'll probably use it going forwards.