George Karnos
Ansys Employee
Can you try starting Workbench by right click and choose: more->run as administrator.
Does this allow you to run?
If not, run: ANSYS 2021 R2-> Product and CAD Configuration (right click and choose run as administrator)
Run through the Check for required prerequisites
If you are missung any run through the Install Required Prerequisites
Then run through Add .NET Security Exceptions for Ansys, Inc Products