Black Screen after champion select

Ive been trying to play league for about 2 days now, but everytime after champion select, aram or normal, it loads up a black screen, it doesnt say disable firewall or check internet connection like it usually does, just a black screen. Its really annoying as i have to wait 20 minutes now to start a game and this is not a problem on my part but riots.Please fix this asap. ( Mac User )