Ensure that the VMM agent is installed and running. If the error persists, restart the virtualization server (%ServerName;) ...

Ensure that the VMM agent is installed and running. If the error persists, restart the virtualization server (%ServerName;) and then try the operation again. 

This error can also happen due to an older version of the VMM agent on the virtualization server. Ensure that the VMM agent is upgraded to the latest version, and then try the operation again.