Game Crashes When Nexus Is Destroyed

Hello Summoners,

I've been having this issue for a while now (maybe a few months) but wasn't really a big deal to me. Now it's crashing every game I play. Whenever the game ends, and right when the Nexus is destroyed my game freezes. I try to ALT + TAB or pull up Task Manager, but I can't because my screen turns black. Then I have to restart by computer. I've tried running the repair on Leagues launcher, but that has not help my issue at all. If someone could please help me out, that would be greatly appreciated!

P.S.

I apologize if there is a post already about this issue, but I have not been able to find it.