When running a backup on a VM, the following error is observed:
"Value cannot be null. Parametername: source"
The VM was pointing to a phantom snapshot that did not exist on the datastore.
See VMware kb for more information http://kb.vmware.com/kb/1005049
In vCenter, go to snapshot manager of the VM
Take a new test non-memory snapshot
Delete all snapshots
Confirm the VM is not pointing to a delta file.
