Error: The Exchange Trusted Subsystem is not a member of the local Administrators group on specified witness server

If you get this error message when you are trying to configure your DAG Witness server you probably needs to do the following to things:

Add the “Exchange trusted subsytem” to the Local Administrators Group of the witness server.


Next you will need to add the witness server to the Exchange Servers Active Directory Group

Restart the server and try to add the Witness server again.