Error from park wrapper: domain.com is already configured

If you get the above error while adding an add-on domain under cPanel.
Then make sure the the enties for the domain do not exists under the below files. If the entires are in the files mentioned you need to remove them

/var/named/domain.com.db
/etc/httpd/conf/httpd.conf
/var/cpanel/users/username remove (dd) related entries to domain,
/etc/userdomains
/etc/localdomains
vim /etc/named.conf remove (dd) related entries to domain
remove dns entry in whm
run /scripts/updateuserdomains

(Renaming or commenting will not help; you will have to remove the entries completely.)