I forwarded your info to our support team, but I’m sure they’ll want to know more about the error you received when you tried to start up PAC Sim. Perhaps a screen shot of the error you see when it fails to start?
A couple of thoughts, though: can you try running PAC Sim as admin? Can you see if port tcp port 22001 is blocked by something IT added, like a firewall? (Telling your IT folks that a program that needs port 22001 might help them help you…)