[Crash] Vayne's Ultimate Problem

So I recently emailed the support staff and they asked me to post my problem here, so here I am.

Over the past few months I've encountered a problem that whenever a Vayne uses their ultimate, whether it be myself, an ally, or an enemy, my game crashes. I only seem to be having this problem with Vayne, and none of her abilities besides her ult causes me to crash. My game most of the time doesn't reconnect either so I have to exit and then reconnect but by the time that happens she ults again and once again my game has crashed. So I was wondering if any of you guys had an idea to what's causing this or if there's anything that I can do to fix this because it's really irritating not being able to play after level six when there's a Vayne in the game.

Any assistance or advice would be greatly appreciated! Thanks!