AttributeError: 'NoneType' object has no attribute '_meta'

[sentry-io]

Sentry Issue: CARE-F99

AttributeError: 'NoneType' object has no attribute '_meta'
(12 additional frame(s) were not displayed)
...
  File "care/facility/api/serializers/patient_consultation.py", line 479, in create
    create_consultation_events(
  File "care/facility/events/handler.py", line 100, in create_consultation_events
    create_consultation_event_entry(
  File "care/facility/events/handler.py", line 42, in create_consultation_event_entry
    value[field] = serialize_field(object_instance, field)
  File "care/utils/event_utils.py", line 34, in serialize_field
    return serialize_field(related_object, sub_field)
  File "care/utils/event_utils.py", line 38, in serialize_field
    field = object._meta.get_field(field_name)