4.25.4 Hotfix released

This is fascinating, I was on 4.25.3 and suddenly I have not been able to open any 4.25 projects.
I am updating now to see if 4.25.4 fixes this, but it was not working on 4.25.3. I restarted my PC and had no updates system-wise, so it seemed bizarre.
CPU would start racing up towards 100% when project loaded up to 39%. No project was getting past 39% mark for some reason. Usually it zips right to 100%.
I’m wondering if some timing-code had been inadvertently introduced to the build, as in “after 11/8/2020, no project load beyond 39%”…It is 2020 after all!

EDIT:
No project will load past 39% on 4.25.4 for me.

EDIT2:
This is related to Raytracing, projects using DX11 load fine, but no project will load with DX12, in either 4.25 or 4.24…
I cannot ope a project in DX11, then switch to DX12, and then load it either. So mode DX12 is not working, projects won’t load past 39%.
Have not update Nvidia drivers in a while, but there was a Win10 update back in Mid October. I am curious if there is some issue here.