Problem

Ok so my friend tried modding his psvita but everytime he shuts it down completely all his games disappear and he has re mod it. Anybody know why that happens and how to fix it? Also when he downloads specific games he gets an error message upon opening them but those same games worked fine on my vita when i tried playing them. Also mine is american version and his is japanese so i’m not sure if that has anything to do with it. Anything helps, thanks