Delirium + Simulacrum Crashes on Laptop + Desktop PC

Noticed that since 9 Aug, I have been crashing in Delirium and Simulacrum.

At first, I thought it was just my laptop not being able to handle it. But I did this on my Desktop PC and the crash continued to happen.

Just realised that the crash happens when I actively use Frost Shield. This happens when I am using both Laptop and Desktop PC.

I highly suspect something is wrong with that skill when I actively use it in big packs of mobs.