I am getting the following error when attempting to install CU15 on one of our exchange servers.
Setup can't use the domain controller 'Site' because it belongs to Active Directory site 'Main Site'. Setup Must use a domain controller in the same site as the computer (other mail server).
The server that is getting the error is setup as our other sites mail server. All of the mail accounts are linked from the other sites DC. I cannot move the server to the main site.