After some more research i found a reddit with people having the same issue. Finally someone figured it out. Here is a working solution, just follow those instructions. www_reddit_com/r/techsupport/comments/3f3yc8/windows_10_app_icons_are_messed_up_after/ctmwagt
Since I have not enough posts yet, I'm not allowed to enter valid links here, just replace these 2 underscores with dots.