[CLIENTBUG]

I was playing a ranked game and alt+tabbed out, and when getting back in the game I could see the top of my screen as a white windowsborder. Also when i'm ingame I can't my camera won't move down so If I want the camera to move I have to play with a fixed camera. I tried restarting the client, shutting down my PC and even re-installing LOL. Does anyone know how to solve this problem? Thanks in Advance!