Problem with Nameservers - Authoritative DNS

[Matt]

Have you contacted your registrar and actually registered the nameservers? You need to provide them with the desired nameservers, and associated IP addresses. Once the nameservers have been registered, then you can use them on your domains.

If the nameservers are not registered yet, you will receive various errors.

Your DNS zone also needs the matching data that you have configured at the registry.

so add this if it does not exist:

ns1 in A 900 xxx.xxx.xxx.xxx
ns2 in A 900 yyy.yyy.yyy.yyy

Where xxx and yyy are the IPs that you were assigned in your welcome email.