Acrobat Pro DC - UI elements have disappeared
version 2017.012.20095
I'm going to delete and reinstall later today, but thought I'd ask here just in case there's a reason this happened.
Suddenly (this morning), the interface for Acrobat has dropped a bunch of UI elements *and* Acrobat no longer appears as one of my open applications when I use Alt+Tab to spin through my list of open apps in Windows.
Here are four (well, three) UI elements that I noticed right away -- close icon on tab, expand/contract icons on left/right panels, frame around 'About' window:

Has anybody seen this happen before and/or know how to prevent it from happening?
