I've setup CE to work with the Plesk plugin (mine is Windows Server), I get the following error in the next page after I try to activate an order:

There was an error creating the domain. CURL operation failed. 7: couldn't connect to host

After I click activate, it stays for a long time and then in the next page shows the above error. I've disabled all firewalls in the server. I first used the hostname of the server in the plugin's "Hostname" field, and that time it was showing the same error, but with "couldn't connect to hostname". Then I entered my domain name in the filed and I get the error as mentioned on above. In the "Plugin Variables", I've entered the Plesk admin login. Any clue ?