Error adding domain group to local group

I am new to Active Directory and DNS. I tried adding a domain group called TSE_Sec_Admins to the Administrators local group.

I get an message:
Processing of object TSE_Sec_Admins failed with the following error: The specified domain either does not exist or could not be contacted.

I can ping the Domain Controller and can see all of the users in the domain from the add dialog box. Any help would be greatly appreciated.