Failed to load 'dgfPublicAssetCertificate' field, cause of 'dgfPublicAssetCertificate'

[2021-03-10T08:04:43.334Z] | mongodb_mirror.mirror | ERROR - Critical error on trying to serialize entry - ["Failed to load 'dgfPublicAssetCertificate' field, cause of 'dgfPublicAssetCertificate'"] | X-Request-ID: acff4665-e9ca-445b-83ba-0a2947b19d50
Traceback (most recent call last):
  File "/usr/local/lib/python3.8/site-packages/schematics/models.py", line 136, in trusted_load
    obj.__data[key] = obj.fields[key](val, context)
KeyError: 'dgfPublicAssetCertificate'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/lib/python3.8/site-packages/mongodb_mirror/mirror.py", line 89, in sync_client
    data = self._serialize_document(data, collection)
  File "/procedure_mirror/procedure_mirror/main.py", line 17, in _serialize_document
    return load_procedure(migrated_data).to_primitive(app_data={'locale': '__all__'}, role='public')
  File "/usr/local/lib/python3.8/site-packages/prozorro_sale/procedure/model_generator.py", line 62, in load_procedure
    return get_procedure_type_from_data(data).trusted_load(data)
  File "/usr/local/lib/python3.8/site-packages/schematics/models.py", line 138, in trusted_load
    raise ConversionError(f"Failed to load '{key}' field, cause of {e}")
schematics.exceptions.ConversionError: ["Failed to load 'dgfPublicAssetCertificate' field, cause of 'dgfPublicAssetCertificate'"]