If you getting the following ERROR while try to create a (parked or new) domain in your cPanel account.
“A DNS entry for “Domain.com” already exists. You must remove this DNS entry from all servers in the DNS cluster to proceed”
Login to server through ssh and execute the following command.
After that try again to re-add he domain.
You can check it through.
grep -R domain.com /var/cpanel/userdata/*
You can see the list of subdomains and addon/parked domains from this file of the user.