Client loads as a tiny little box after a game.

After a game when I click the Victory/Defeat button, the client loads as a little black sliver and I can't see anything in the post game. The only way out is to close and restart the client. I ran a maintenance which didn't solve it. I also uninstalled League, rebooted my computer and reinstalled and it still does it. It must be a bug. I cannot see the post game report or report any players or anything please fix!