Error deploying Virtual Appliance: "Error:UnhandledException:System.NullReferenceException: Objec (96221)

When attempting to deploy a Virtual Appliance using the automatic deployment wizard in vRanger, the process fails with:

"Error:UnhandledException:System.NullReferenceException: Object reference not set to an instance of an object.
at Vizioncore.vRanger.VirtualizationService.Vmware.Vim.LeaseProgressMonitor.WaitForLeaseRead"

A possible cause is that the VMware hosts may have been upgraded recently and that vRanger is not connecting with the VMware environment as it should.

1. Please remove your virtual center and any lone hosts from the vRanger inventory
2. Then readd all components of inventory back into vRanger
3. Retry the Virtual Appliance Deployment