Backup of Virtual Machines on VMware Workstations

All,

I have a VMWare Workstation enviroment and would like to back up some of the VMs, but when I try to add the credentails, I get the following error:

14:22:32.381 [5040.11360] <2> test_VM_cred: server returned HostAgent sApiType
14:22:32.381 [5040.11360] <2> test_VM_cred: server did not return VirtualCentertype

Does Netbackup work with VMWare Workstation and if so, what is the procedure for configuring it?

Thanks

David