[FIXED, Mac] Game crash after champion select (after spectate Sona)

Me and my girlfriend spectate a accidentally before we know the bug. And we both can't play any game after that. But we find out the solution, it worked for us:

Go and create a custom game. After you pick a champion, screen goes black. Now, press random keys for like 20 seconds. (any key such as enter, shift, esc, tab, option, command, control.) you have to press at least two of them together at the same time!!!

the game runs no problem after that

good luck