[sw rec]

You’re not alone with the video issue....I’ve spent HOURS and HOURS trying everything I know how to do, and everything suggested in the e-mail I got from AVID support, and all I get when trying to enable the video engine is, it getting stuck in a loop trying to initialize. Shoot, I even re-downloaded & extracted the installers in the hope that it was something as simple as a corrupt installer.
This suggestion:

a. Remove this folder (even if there is nothing inside):
C:\Program Files\Avid\AVX2_Plug-ins\AMA

b. Remove all the plug-ins inside of:
C:\Program Files\Avid\AVX2_Plug-ins

Resulted in Pro Tools hanging on the opening splash screen and not launching AT ALL. So I uninstalled-reinstalled EVERYTHING, and after days of futzing around with it, I’m back where I started. (By the way, there’s numerous reports of omf imports being broken in 2020.3)
If I need to bring video into it (which I do, frequently) my best option is my 10.3.10 co-install, which Avid says “isn’t Win 10 compatible,” but at least IT works!
I had let my support plan lapse at PT HD 12.4, and frankly feel like I’ve been had, paying over $1k to get these updates that have crippled my workflow. But I don’t foresee making that mistake again. As the old saying goes, fool me once, shame on you. Fool me twice, shame on ME. 12.4 is looking pretty good again.