On a cPanel server if you get the error: Error from park wrapper: domain.com is already configured while adding an add-on domain under cPanel. Make sure to remove the domain.com entries from:
/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.)
