So I fixed mine!
I'm pretty sure it was due to my system drive getting full
(video editor cache files in the background) and some pref file must've got corrupted
I wound up uninstalling PT, then using this little freeware app to nuke all the hidden or hard to find Avid Pro Tools pref files and databases, (might come in handy for you if you didn’t know about it, another engineer in ATL turned me on to it )
http://petegates.com/pg-pt-prefs.htm...QDR65pcG7uNoHQ
then reinstalled PT
I didn't have to do anything to the OS
Hope this helps, good luck...