KeyError: 'status' when trying to schedule spider

I am getting this error when trying to schedule a spider. This is happening with version 2.3.1

Traceback (most recent call last):
  File "/home/molveyra/.local/share/virtualenvs/mollie-AtuAN_AE/lib/python3.8/site-packages/scrapinghub/legacy.py", line 157, in _decode_response
    if data['status'] == 'ok':
KeyError: 'status'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/molveyra/.local/share/virtualenvs/mollie-AtuAN_AE/lib/python3.8/site-packages/scrapinghub/client/exceptions.py", line 69, in wrapped
    return method(*args, **kwargs)
  File "/home/molveyra/.local/share/virtualenvs/mollie-AtuAN_AE/lib/python3.8/site-packages/scrapinghub/client/__init__.py", line 19, in _request
    return super(Connection, self)._request(*args, **kwargs)
  File "/home/molveyra/.local/share/virtualenvs/mollie-AtuAN_AE/lib/python3.8/site-packages/scrapinghub/legacy.py", line 143, in _request
    return self._decode_response(response, format, raw)
  File "/home/molveyra/.local/share/virtualenvs/mollie-AtuAN_AE/lib/python3.8/site-packages/scrapinghub/legacy.py", line 169, in _decode_response
    raise APIError("JSON response does not contain status")
scrapinghub.legacy.APIError: JSON response does not contain status

Read scrapinghub/legacy.py, especially _request and _decode_response, then reproduce spider scheduling with version 2.3.1. Inspect the JSON response that lacks status and trace how it is produced; done means the scheduling failure is explained and the error path is covered by the repository's existing tests.