Why can't I start a game?

I've been trying over and over to begin a game. Everything is fine up until the actual game starts, then it INSTANTLY pops up a system error saying it needs to terminate the program.

I know Riot said to re-login to get passed this issue, but that is not working. Even tried an old account and still nothing....? Should try another computer? Different internet? Its so annoying to wait 3hrs to play again, then I can't even start a game. Not even a practice or custom will start. So, awesome, got a reworked Nunu and I cant even try until who knows when.....

[slayer-jinx-unamused] [zombie-brand-facepalm] [sg-shisa]