E: 16:36:13 Traceback (most recent call last):
  File "./picard/releasegroup.py", line 141, in _request_finished
    self._parse_versions(document)
  File "./picard/releasegroup.py", line 108, in _parse_versions
    name = " / ".join([release[k] for k in namekeys]).replace("&", "&&")
TypeError: sequence item 2: expected str instance, NoneType found