Error when deleting pipeline

[Tommos0]

[2018-11-20 08:26:06,060] ERROR in app: Exception on /pipelines/5bf1c5461a114e008da23e4f/delete [GET]
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/site-packages/flask/app.py", line 1982, in wsgi_app
    response = self.full_dispatch_request()
  File "/usr/local/lib/python2.7/site-packages/flask/app.py", line 1614, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/usr/local/lib/python2.7/site-packages/flask/app.py", line 1517, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/usr/local/lib/python2.7/site-packages/flask/app.py", line 1612, in full_dispatch_request
    rv = self.dispatch_request()
  File "/usr/local/lib/python2.7/site-packages/flask/app.py", line 1598, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/newsgac/newsgac/users/view_decorators.py", line 16, in decorated_function
    return f(*args, **kwargs)
  File "/newsgac/newsgac/pipelines/views.py", line 167, in delete
    pipeline.delete()
  File "/newsgac/newsgac/pipelines/models.py", line 98, in delete
    ace.delete_pipeline(self)
  File "/newsgac/newsgac/ace/models.py", line 42, in delete_pipeline
    self.save()
  File "/newsgac/newsgac/common/mixins.py", line 22, in save
    super(CreatedUpdated, self).save(**kwargs)
  File "/usr/local/lib/python2.7/site-packages/pymodm/base/models.py", line 476, in save
    self.to_son(), upsert=True)
  File "/usr/local/lib/python2.7/site-packages/pymongo/collection.py", line 925, in replace_one
    collation=collation, session=session),
  File "/usr/local/lib/python2.7/site-packages/pymongo/collection.py", line 851, in _update_retryable
    _update, session)
  File "/usr/local/lib/python2.7/site-packages/pymongo/mongo_client.py", line 1248, in _retryable_write
    return self._retry_with_session(retryable, func, s, None)
  File "/usr/local/lib/python2.7/site-packages/pymongo/mongo_client.py", line 1201, in _retry_with_session
    return func(session, sock_info, retryable)
  File "/usr/local/lib/python2.7/site-packages/pymongo/collection.py", line 847, in _update
    retryable_write=retryable_write)
  File "/usr/local/lib/python2.7/site-packages/pymongo/collection.py", line 817, in _update
    retryable_write=retryable_write).copy()
  File "/usr/local/lib/python2.7/site-packages/pymongo/pool.py", line 584, in command
    self._raise_connection_failure(error)
  File "/usr/local/lib/python2.7/site-packages/pymongo/pool.py", line 745, in _raise_connection_failure
    raise error
InvalidDocument: Cannot encode object: <newsgac.common.fields.WrappedObject object at 0x7f146d96fc10>