Game crashes every time at champion loading screen

League of legends crashes and I get a bug splat every time I try to enter a game. I have repeatedly tried to enter games (don't worry, they have all been custom games after I discovered the problem trying to enter a normal game) and without fail when the countdown hits zero, the screen goes black as if it is about to go to the champion loading screen, and then I get a bug splat stating the game has crashed. I sent in an error report the last time it happened. Hitting reconnect to game doesn't work either. The screen will just go black again and then I get a bug splat. I have tried updating my drivers, updating dirextx, doing a clean reboot of my system to make sure that other programs weren't causing LoL to crash, scanning and repairing, and completely uninstalling and reinstalling the game. Nothing has worked. It might be worth noting that I recently upgraded to windows 10, however I tried running the game on earlier versions (windows 7, 8, and xp) and still experienced the same problem. Any insight as to how to fix this would be appreciated. Thanks!