co-domains adding error
I've a problem adding a co-domain. I've browsed and searched the forum and I saw many similar questions but I did not find any hint for my problem.
I have the need to point aaa.domain.com to one site and bbb.domain.com to another site but when adding the second one I get the error
"The Domain belongs to another client"
I'm sure that the sub-domain bbb of domain.com has never been used (nor trashed) but I get this error. Could this be related to the presence of domain.com (without any third level subdomain) in another site ?
Thank you for any suggestion,