I just upgraded to 5.01, but I could not install it. At first, it said that my password was incorrect (even though I have it stored in Dashlane). Then it wouldn't allow me to try again and instead came up with the warning "simplify 3d failed to activate the software. the software will now exit". I uninstalled 4 times and then installed version 4...(and deleted anything to do with simplify except profiles) The same warning appeared after each reinstall.
After you uninstall, does your S3D customer profile show that the license has been deactivated? I've been having trouble with 5.0.1, and one issue is that it doesn't release the license after uninstalling. I have to install 5.0.0 and uninstall that to release the license.
It's not a solution, but it might help with your troubleshooting.
I did receive advice from 3D simplify support " We have seen very few reports of this error message, so I want to confirm if the problem is only specific to this one computer." I guess I'm one of the lucky ones... I sent them my computer specs (a high-end Asus gaming laptop).
I'd try the installing version 5 method, but this version is nowhere to be found in a Google search or on Simplify's website. They only have 5.0.1