Command Line issues

Hi guys

Im having an issue with my bad login command line command. I get the below in my logs. Anyone know why?

2017-09-27 13:12:33 ERROR (Thread-7) [homeassistant.components.sensor.command_line] Command failed: grep -c 'Login attempt' /home/reuben/.homeassistant/home-assistant.log
2017-09-27 13:13:59 ERROR (Thread-11) [homeassistant.core] Error doing job: Future exception was never retrieved
Traceback (most recent call last):
  File "/usr/lib/python3.5/concurrent/futures/thread.py", line 55, in run
    result = self.fn(*self.args, **self.kwargs)
  File "/home/reuben/.local/lib/python3.5/site-packages/homeassistant/components/logentries.py", line 59, in logentries_event_listener
    requests.post(le_wh, data=json.dumps(payload), timeout=10)
  File "/usr/lib/python3.5/json/__init__.py", line 230, in dumps
    return _default_encoder.encode(obj)
  File "/usr/lib/python3.5/json/encoder.py", line 198, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "/usr/lib/python3.5/json/encoder.py", line 256, in iterencode
    return _iterencode(o, 0)
  File "/usr/lib/python3.5/json/encoder.py", line 179, in default
    raise TypeError(repr(o) + " is not JSON serializable")
TypeError: datetime.datetime(2017, 9, 27, 12, 30) is not JSON serializable