Cannot set single display device via VNC display error when updating a VM Instance Type

Issue

• Cannot set Instance Type of a VM via the RHV 4 Python SDK
• Trying to provision or edit VMs in RHV 4 via the Python SDK returns an error like the following:

Traceback (most recent call last):
  File "/usr/local/lib/python2.7/site-packages/fabric/main.py", line 743, in main
    *args, **kwargs
  File "/usr/local/lib/python2.7/site-packages/fabric/tasks.py", line 427, in execute
    results['<local-only>'] = task.run(*args, **new_kwargs)
  File "/usr/local/lib/python2.7/site-packages/fabric/tasks.py", line 174, in run
    return self.wrapped(*args, **kwargs)
  File "/Users/ccrawford40/git/capella/uops-systems-code/fabric/builds/rhev_ops.py", line 103, in rhev_dr_import_config
    instance_type=vm_instance_type_obj
  File "/usr/local/lib/python2.7/site-packages/ovirtsdk4/services.py", line 24130, in update
    self._check_fault(response)
  File "/usr/local/lib/python2.7/site-packages/ovirtsdk4/service.py", line 98, in _check_fault
    Service._raise_error(response, fault)
  File "/usr/local/lib/python2.7/site-packages/ovirtsdk4/service.py", line 71, in _raise_error
    raise Error(msg)

ovirtsdk4.Error: Fault reason is "Operation Failed". Fault detail is "[Cannot edit VM. Cannot set single display device via VNC display.]". HTTP response code is 400.