League sometimes crashes midgame.

Hello, I've been having an issue for quite a while now with LoL.

So, when I find a game, it goes to the champion screen, and I do the normal thing. Pick my champ, of course. Then, here comes the risky part for my game. Every so often, my game crashes. It's random; it crashes when I'm at 100% loading, when the game just starts, or near the end. It all freezes, playing the background music for a few seconds, then it stops. It then stays there for a while until the "League of Legends has stopped working" dialog appears. I then try to open the Riot Client by clicking the logo in the taskbar, but when it opens it shows the Maestro error. I then have to reopen the client and start all over.

And I've gotten 20:00 minutes of low priority stuck on me now! And it keeps crashing, so it keeps resetting! I need a fix for this please!

I'll happily post anything tech related if I have to.