Symptoms

Unable to create subdomain or domain alias or update domain's DNS settings:

Unable to create the DNS zone because its superzone belongs to another user

Cause

Users cannot create new subdomains and domain aliases in the DNS zones belonging to other users because Forbid users to create DNS subzones in other users' DNS superzones is enabled. By default, this option is disabled.

Resolution

Disable Forbid users to create DNS subzones in other users' DNS superzones option in Tools and Settings > Server Settings