Client closes after champ select and doesn't let me connect to game...

So I've had this bug happen to me four times in a row now. My client is completely normal up until I decide I want to play an actual game. I select my champ, have everything completely set up, then BLAM. As soon as the client switches from champ select to the loading screen, my game closes with no error messages or anything. When I go to reopen league. I type in my password, click the login button, and my game closes again. This will continue until my league match is completely over. I have repaired my client twice now and still no signs of change have popped up.

Someone. Help. Please.