Game keeps on crashing

So when im in champion select, everything seems to be fine, but when the game launches it crashes all the time and ill get to the " you left a game in progress please reconnect" screen, and when i press reconnect it crashes again. I also de and reinstalled it. Restarting it or my Pc doesnt help either. Does anyone have the same problem? Can you help me please? D:

Ty anyways ^^