Unfotunatly this game (and several others I've worked on) suffer from an unfortunate Unreal Engine issue. The explaination I was given from a friend who had the same problem with one of her games, is that UE4 will install some stuff to run it on your pc, but won't update those files if you later play an older game. Because the game is built using an older version of the engine than the one your system expects it can run into bugs and crash. I have the same issue when I try to play now. I suspect this can be resolved by finding out where unreal stores these files and deleting them (though I've not had a chance to look into how to do this, but googling the issue may find you some results!) That said, my friend may also have just been wrong, but seeing as the issue effects a few of my Unreal projects made around the same time as Parsnip, I suspect it's roughly accurate :(