After trying everything suggested here and elsewhere, I still could not get Simplyfy3D or several other programs to start. In Windows 10 Event viewer/Application it always showed an "unknown error" event 1000.
I fixed my issue by disabling the “Intel UHD Graphics 630” adapter. Open Device Manager, select Display Adapters, right click, and “disable” the adapter. DO NOT select “uninstall device”, it will automatically re-install itself, just disable it.
If you are having the same issue with programs not starting after Microsoft’s Windows 10 October 2020 update, you may not have the exact same adapter as listed above but it was the UHD Graphics adapter causing my problem – ok, not so much the adapter as whatever they messed up in the latest update for the graphics drivers.