This monitor verifies that at least one reliable time server is available.
It will perform a 'nltest /dsgetdc: /gtimeserv' operation per the specified configuration interval.
Possible causes include the following:
No DCs were configured as a reliable time server.
The server was unable to contact the domain.
Ensure that the domain is online and functioning correctly.
Ensure that at least one DC is configured as a reliable time server.
For more information, see:
How to configure an authoritative time server in Windows Server