If you encounter this error while taking snapshot or cloning the windows machine or while during V motion of machine, you need to check 3 things:
1) check whether vmware tools service is running or not and whether the tools is updated to latest version or not
2) Check Virtual disk service is running or not
3) Check that Volume shadow copy is running or not.
All the 3 services mentioned above must be in running state while cloning/migrating machine from one Esxi host to other.