There's only one way to know if Virtual Standby (VS) VM is good: start it. However, caution need to be exercised since that VM is an exact clone of the protected machine and having 2 exactly same machines in the same network can be disastrous.
So, in order to verify if VS VM is good, please access its settings using a hypervisor (Hyper-V host, vSphere client, etc) and disable its network card. It's also possible to change NIC VLAN to the dedicated one, where there'll be no communication between VS VM and the original protected machine.
After that, boot the VS VM to make sure that it's bootable and contains all data.
