Error at my Add-on Domain

[shielatio_2093]

I am having an error upon registering an add-on domain.

"Addon Domain Additions
-There was a problem creating the addondomain.
--Show Details
---Error from park wrapper: shielatio.tk is already configured."

This is because I first add my dns to my dot.tk account before I add it to my add-on domain.

I also tried additional domain, shielamaytio.tk, yet same error occured.

Hope you can help me resolve this problem. Because my url shielatio.tk produce this kind of error:

"If you feel you have reached this page in error, please contact the web site owner:

webmaster@shielatio.tk
It may be possible to restore access to this site by following these instructions for clearing your dns cache.
If you are the web site owner, it is possible you have reached this page because:

The IP address has changed.
There has been a server misconfiguration.
The site may have been moved to a different server.
If you are the owner of this website and were not expecting to see this page, please contact your hosting provider."

[garrettroyce]

I show that domain is not configured to any X10Hosting account. I have requested a staff member assist you with this problem.