Your Primary Name Server was not in the list of name servers given to us by the root.
If your name server is not listed at the root this could cause impaired/incorrect lookups for your domain.
The Primary Name Server is the name server declared in your SOA file and is usually the name server that reads your records from zone files and is responsible for distributing that data to your secondary name servers. This problem is present when this primary name server is not included in the parent referrals and is almost always accompanied by a Local Parent Mismatch problem.
Here a primary name server acquires information about one or more
zones by reading master files from its local file system, and
answers queries about those zones that arrive from foreign
resolvers. [RFC 1035]
DNS Propagation Check
If your Primary Name Server is not listed at your Parent or is not responding, then our DNS Propagation test tool will not operate properly. You will most likely also be experiencing other real world problems with DNS queries for your domain. Users with Basic or Pro accounts can contact our Support Team for assistance with understanding any DNS warnings or errors with specific information about your domain. If you are still a free user, upgrading your account will give you access to support as well as many other benefits.