League will close as if I pressed alt+tab in game

As the title says, I'll be playing the game and for some reason it will just randomly close out as if alt+tab was pressed. Is this just me or does this happen to other people too? No notification is popping up either, it just randomly closes out. It's been doing this for a while now and it's very rage inducing when I die or miss out on a kill because of it (it's happened a lot).