Champion select client Bug

So I was doing rank game, after I accept the queue and pop into the champion select screen, there was message pop on bottom right said I disconnected and the screen turned Black. I can not click anything and I can not select champion. The only way to leave is close the client and that will cost me 3 lp lose. This bug is so annoying and unfair to player. Please fix this bug.

Edit(ScreenShot when the bug happend): http://postimg.org/image/vlkd2od11/