Thanks for that clarification, Win.

Now that I understand the login credential matching requirements for MPI, I think I'm almost on my way.

I've gotten parallel solving to work on various combinations of machines, but I've only been able to do it by turning off firewalls of the remote compute nodes.

You mentioned in your initial response that I need to exclude the entire directory C:Program FilesAnsysEM from the firewall, but I haven't figured out how to exclude a directory from the firewall. All the websites I have found only tell me how to make exceptions for individual processes. I would consider going this route, but it is not clear to me which individual processes are associated with C:Program FilesAnsysEM.

Can you refer me to a procedure for excluding an entire directory from Windows 10's firewall? (I am not running any 3rd-party software.)

Almost there! Thanks so much for your help.