Existing NS records block new record creation

As you try to create a new DNS record, Cloudflare displays the following error:

NS records with that host already exist. (Code:81056)

​​ Causes

When a child domain (blog.example.com) of your domain (example.com) has been set up as a separate subdomain zone, corresponding NS records must have been placed within the parent zone.

When you are managing DNS records for the parent zone (in this example, example.com), you cannot create IP address resolution records (A, AAAA, or CNAME) with a name that specifies the same subdomain that already exists as a separate subdomain zone.

​​ Solution

Before creating such records, remove any NS records with the same name.