Have you tried running the SOLIDWORKS Rx tool?
It may highlight something that is causing an issue.
It will also give you the option to open SOLIDWORKS it in safe mode.
My VAR repaired my issue with framework very quickly...
no idea how it was done...
am sure he removed and reinstalled .net framework though
Okay I got a message that the problem has been fixed.
In the end, the end user uninstalled and reinstalled Solidworks 2017.
So I guess .net framework and c++ got repaired, then repairing Solidworks wasn't' enough; Solidworks had to be uninstalled / reinstalled...
Thank you all