When trying to add a new domain in WHM, you may get an error like this:
Account Creation Status: failed
Sorry, a DNS entry for domainname.com already exists, please delete it first (from all servers in the dns cluster)
This means that a DNS Zone File already exists for this domain. Simply click to the "Delete a DNS Zone" link (in the WHM left-hand menu) and remove the domain name you are trying to add. Now you can reattempt the account creation.
If you still need assistance, feel welcome to contact us.