I had the EXACT same problem in PD15.
The crashing occurred after I installed a new graphics card and was relentless. I tried everything, even joined the Nvidia forum seeking help.
Then, one day, while capturing analog video my computer froze and then crashed.
The next time I opened PD and tried to alter a menu background, it worked.
Sorry I never figured out what or why, it just started working after the freeze crash.
I suspect something about your video card driver or installation.
HP Envy Phoenix/4thGen i7-4770(4@3.4GHz~turbo>3.9)
Nvidia GTX 960(4GB)/16GB DDR3/
Canon Vixia HV30/HF-M40/HF-M41/HF-G20/Olympus E-PL5.
Tape capture using 6 VCR, TBC-1000, Elite BVP4+, Sony D8 camcorder with TBC.
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