Sites can show the Default Plesk Automation Page if they are suspended, they do not resolve properly, or a webserver is misconfigured. This can also be caused by failed tasks.

Resolution

Check all the points below:

1. Make sure there are no failed tasks regarding the relevant subscription in System > Task Manager.
2. Check that the domain resolves correctly. You can check this using the nslookup utility:

   nslookup domain.tld
   Server:  ns.domain.tld
   Address:  10.47.7.77
   
   Non-authoritative answer:
   Name:    domain.tld
   Addresses:  10.5.55.5
   

3. Make sure the domain is not suspended. You can check this in the Customer Control Panel, on the Websites & Domains tab.
4. Try to reconfigure the domain with the following command (to be executed from the Management Node):

   /usr/local/psa/admin/sbin/httpdmng  --reconfigure-domain <_your_domain_name_>