Symptoms
You get an error when trying to park a subdomain of the main domain with "Share document root" selected.
The error:
Sorry, you can not add a DNS record for a subdomain of another user’s domain.
Description
When a cPanel account has an owner set to a reseller that doesn't exist the cPanel user is not able to create a subdomain of the users main domain and parked with "Share document root" selected.
We've opened an internal case for our development team to investigate this further. For reference, the case number is CPANEL-50991. Follow this article to receive an email notification when a solution is published in the product.
Workaround
Modify the users configuration file /var/cpanel/users/$user
Change the OWNER= line to
OWNER=root
Execute:
/usr/local/cpanel/scripts/updateuserdomains