Premiere Pro (2017.1.2) opens fine and I can edit a project without problem, but when I try to change to a different project (File>Open Project or File>Open Recent) Premiere hangs and doesn't respond. Likewise, whenever I try to quit Premiere. I need to do a Force Quite (Premiere in red, says not responding). Then I can open a new project. Any idea what's happening? MacPro, 32 GB memory, OS X Yosemite 10.10.5.