George Karnos
Ansys Employee

Try the following:

Close all Fluent/Ansys Programs.

Open Windows File Explorer and type in the following in the address line:

%APPDATA%\Ansys

This will take you to your APPDATA\Ansys directory.

You should see a directory named:  v231    (Or version you are using)

Rename that directory to v231.old

Now try to run.