PyXFormError: There has been a problem trying to replace ${Q64} with the XPath to the survey element named 'Q64...

[ukanga]

PyXFormError: There has been a problem trying to replace ${Q64} with the XPath to the survey element named 'Q64'. There is no survey element with this name.
(9 additional frame(s) were not displayed)
...
  File "rest_framework/views.py", line 486, in dispatch
    response = handler(request, *args, **kwargs)
  File "rest_framework/mixins.py", line 21, in create
    self.perform_create(serializer)
  File "rest_framework/mixins.py", line 26, in perform_create
    serializer.save()
  File "rest_framework/serializers.py", line 215, in save
    self.instance = self.create(validated_data)
  File "onadata/libs/serializers/merged_xform_serializer.py", line 182, in create
    validated_data['xml'] = survey.to_xml()

PyXFormError: There has been a problem trying to replace ${Q64} with the XPath to the survey element named 'Q64'. There is no survey element with this name.

Aha! Link: https://ona.aha.io/features/PROD-500