After renaming the server and restarting DataMiner I now get an error when I try to log in with the local Administrator account.
Connection failed - External authentication failed.
In the Cube logging I see the DataMinerSecurityException 'attempt to use an unauthenticated connection'
What's the best procedure to rename a server?
well, we got it working. When we wanted to revert, we stumbled across entries in the DMS.xml that still were showing the old server names.
We guess that the files were saved too early, before Dataminer was stopped and so somehow old entries were written back.