"A critical error has occurred and the process must be terminated."

So yesterday morning I played a game of nexus blitz, all was well, ended up winning, went to play the next game and my game crashed after champ select giving me the error above and asking if I would like to create a crash dump. I've had this happen before and the last few times it seemed to fix itself after a fresh reinstall, or restart etc (It wasn't the same fix nor can I pin exactly what fixed it.). But this time around nothing seems to be doing the trick, Ive run the Hextech repair tool, completely reinstalling, checking my firewall settings, and restarting my computer. Any help would be appreciated as I am completely clueless as to what I need to do. Thank you <3