It seems that any place the Sitecore CM where a modal dialog would pop up has stopped working and I haven't been able to figure out why. I see the same behavior in both Chrome and FireFox. The error description is a bit more descriptive in FireFox:
Uncaught TypeError: top._scDialogs is undefined. It seems both jsnlog.js and sitecore.js are trying to call that undefined function.
It appears that dragging and dropping is also broken and I see messages in the Console about
scDraggable not being defined as well.
Any ideas what could be causing this?
I've tried rebuilding and re-deploying. The same codebase is working correctly on our QA environment. The environment that has this issue is DEV environment.