When installing the server application, I hit "Create a new domain name" but oddly got an error "Cannot find the domain name. Please check the information and try again."

I then uninstalled, created a domain name on the website, and reinstalled.

This time I checked off "Use an existing domain" and got the same "Cannot find the domain name" error.

Any ideas on what I can do?

I figured it out. My firewall was blocking.