Resource Record of type A with these attributes already exists in the system

Symptom

"Resource Record of type A with these attributes already exists in the system error' received when trying to update TTL on an "A" Record.

Steps to Test

1. Click Domains
2. In the search bar type domain.com.  The result display both domain.com and sub.domain.com
   1. If IP is known, search with the IP
3. Click sub.domain.com, verify that that there is sub.domain.com "A" record in the "A Records" section
4. Click Domains
5. Click domain.com, verify that that there is sub.domain.com "A" record in the "A Records" section

Root Cause

sub.domain.com resource record exists in both sub.domain.com and domain.com zones

Steps to Resolution

1. Add these NS records to domain.com. zone:
   sub.domain.com. 86400 IN NS pdns1.ultradns.net.
   sub.domain.com. 86400 IN NS pdns2.ultradns.net.
   sub.domain.com. 86400 IN NS pdns3.ultradns.org.
   sub.domain.com. 86400 IN NS pdns4.ultradns.org.
   sub.domain.com. 86400 IN NS pdns5.ultradns.info.
   sub.domain.com. 86400 IN NS pdns6.ultradns.co.uk.
2. Delete sub.domain.com "A" record from progress.com. zone.