Exception in StreamBackend

[crocket]

mopidy-2.2.2

ERROR    StreamBackend backend caused an exception.
Traceback (most recent call last):
  File "/usr/lib64/python2.7/site-packages/mopidy/core/library.py", line 19, in _backend_error_handling
    yield
  File "/usr/lib64/python2.7/site-packages/mopidy/core/library.py", line 237, in lookup
    result = future.get()
  File "/usr/lib64/python2.7/site-packages/pykka/threading.py", line 52, in get
    compat.reraise(*self._data['exc_info'])
  File "/usr/lib64/python2.7/site-packages/pykka/compat.py", line 12, in reraise
    exec('raise tp, value, tb')
  File "/usr/lib64/python2.7/site-packages/pykka/actor.py", line 201, in _actor_loop
    response = self._handle_receive(message)
  File "/usr/lib64/python2.7/site-packages/pykka/actor.py", line 295, in _handle_receive
    return callee(*message['args'], **message['kwargs'])
  File "/usr/lib64/python2.7/site-packages/mopidy/stream/actor.py", line 65, in lookup
    requests_session=self.backend._session)
  File "/usr/lib64/python2.7/site-packages/mopidy/stream/actor.py", line 131, in _unwrap_stream
    not scan_result.mime.startswith('text/') and
AttributeError: 'NoneType' object has no attribute 'startswith'