I installed the GA release on Friday and tested the majority of our pages - but didn’t think about the fact that most of our users are on IE … or that this would make a difference. (I’m on IE 9, and would guess that most of our users are, too.)
This morning, the vast majority of my pages don’t work in IE - action framework (seems to mostly be affecting tabs) doesn’t load anything (models or components). Even the page builder is out of sorts: