When trying to replicate any VM from/to certain host all tasks/jobs fail with: Error Message: Object Reference not set to an instance of an object.
Please check "Licensed Features" on your ESX(i) host so it doesn't look like this:
As you see there is nothing in "Product Features" including "vStorage APIs" or Hot-Pluggable virtual HW (Hot Add)
The VMware licensing is not applied correctly or missing.
This is correct image how VMware Enterprise licensing should look:
Please reapply or add licensing to your ESX hosts.