The requested URL could not be retrieved

While trying to retrieve the URL:

The following error was encountered:

Unable to determine IP address from host name for

The dnsserver returned:

Name Error: The domain name does not exist.

This means that:

 The cache was not able to resolve the hostname presented in the URL. 
 Check if the address is correct. 

Your cache administrator is root.

Generated Tue, 20 Mar 18 20:37:25 GMT (squid/2.6.STABLE21)