Addon Domain issue, please help

[delphiman]

When I try to add a domain to my addon domain www.mydomain.org (This is not my primary account domain) but then I got an error emssage:

There was a problem creating the addondomain. Show Details
Error from park wrapper: Sorry, cannot determine nameserver IPs. Please make sure that the domain is registered with a valid domain registrar.

Can anyone help me how to solve this?

Thanks

[cech]

Adding the new registered domain could take a while to propagate the DNS of all servers on the Internet. Be patient, the addon should become available shortly.

[delphiman]

This is not a newly registered domain. This is a 5 years old domain and is currently running with different host. I contacted hostican support then they added it for me

What I don't understand is that why I could not and they can?

[Merlin]

The HostICan admins are the hosting kings. I do not want to know how they can fix the problems, but more importantly for me, is that they can fix any problem.