Sorry, a DNS entry already exists, please delete it first (from all servers in the dns cluster) - WHM

This situation arises when you are using DNS cluster for your server's for the DNS , When trying to add a new domain in WHM, you may get an error like

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Account Creation Status: failed
Sorry, a DNS entry for domainname.com already exists,
please delete it first (from all servers in the dns cluster)
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This means that a DNS zone file already exists for this domain. Now follow the steps listed below to resolve this issue.

Task 1: Terminate the Account in WHM (Web Host Manager)

1)Login to WHM.
2)Go to Account Functions > Terminate an Account.
2)Select account to terminate.
3)Select the Box: I understand this will irrevocably remove all the accounts  that have been checked select it.
4)Always delete zone-file too.
5)Click Destroy Selected Accounts.

When WHM has completely removed the account, the following confirmation message will appear on the bottom of the screen: All Account Terminations Complete!

Now re-attempt the account creation if you still face the same error follow Steps Below.

Task 2: Confirm DNS Entry for the Domain has been Removed.

Now, you  have to delete the DNS entry.Go to DNS Functions > Delete a DNS Zone area in WHM.

If the DNS zone is still listed:

1)Click on the domain name you wish to remove.
2)Click Delete.
3)In next page, click Delete to confirm and we are done.

After completing the steps above, you can re-attempt the account creation.