Been happening to me too all morning for no apparent reasons.
1. open last capx version
2. "close" any layout in the ribbon menu
3. from project window, right clicking to open it again. CRASH
But, seem to have found a workaround. Previously, I had installed the 64 bit version of C2 in (c:/program) directory
1. completely remove everything for a fresh install. Reboot.
2. tried to install the 32bit version. Reboot. NO SUCCESS, Same behavior.
But then I did a fresh install of C2 on a USB flash drive. guess what...Now it is working.
So if it can help anyone, maybe try this yourself.