Constantly getting buffer underflow error and game crashing post-update

As the title says. I'm going through act 7 in the campaign (around Vaal temple) and I keep getting a buffer underflow error and my game hard crashing. This has never happened to me prior to today's update. Anyone else having the same issue?

happening to my dad right now actually. he was playing fine yesterday. so far have tried fresh reinstall, switching renderers, updating GPU. nothing is working

Getting same error here. No crashes since league launch, and now I cant do anything without getting this error. Even just sitting in hideout.

getting this error too but it stops when i removed all my mtx