Often when I /reloadui (to send listings to TTC after banking and selling), the UI breaks completely.
If it happens, at first there's a white square that's closeable in the corner, like the size and location of a treasure map sketch. Then I can't open my inventory or do ANYTHING UI-related. This error pops up and after that nothing is clickable, no shortcuts work. Unfortunately reloading it again doesn't help; the only way to fix things is to log out / back in.

I can't find anything about error 8CBCE40B online. I'm guessing it's addon related? Here's a list of what I run:
It's been happening for months, probably over a year. Makes me nervous to reloadui. But I don't want to play without my UI addons for long enough to test which this could be.