[CRASH] Graphic Bug

Hi,

I've got a problem with the League. During gameplay effects just stop working, i can move, i still lose health, but i cannot see anything. after that bug i need to relog but sometimes few times per game. It looks like on the movie . Recently i changed my computer (an upgrade from MSI GT680 to the Lenovo Y700 (i7 6700hq, 16GB ram, Geforce GTX960m), but the issue didn't solved so i think it might be a problem with a router or smt.

Please help cause im dying to play LOL without bugs...