Unable to Add Domain

An error is thrown by cPanel when trying to add an addon domain. The issue can be related to not having "Allow Remote Domains" enabled within Root WHM or needing to reinstall DNS Admin.

Possible error messages are:

(XID 7ptdz2) Sorry, the domain is already pointed to an IP address that does
   not appear to use DNS servers associated with this server. Please transfer
   the domain to this servers nameservers or have your administrator add one of
   its nameservers to /etc/ips.remotedns and make the proper A entries on that
   remote nameserver.

(XID x2urtx) The system failed to read up to 16 KB from a file handle because of an error: Connection reset by peer.

Fix Error Regarding IP Address

1. Log into Root WHM
2. Navigate to Tweak Settings, located in Server Configuration
3. Select the Domains tab
4. Locate Allow Remote Domains and select ON
5. Scroll to the bottom and click the Save button