Random Freeze and Screen Blackout

I'm not sure if it's just my computer, but has anyone else experienced a random freeze in the game and then the screen going black? It just happened to me in an aram twice. The first time it occurred like I just said but the second time it was only a freeze without the black screen. It only lasted a 1 or 2 seconds. If it means anything, I recently uninstalled and reinstalled LoL due to a "this application was unable to start correctly" error (this fixed the problem).