Met Office error in home-assistang.log

This error is present in my home-assistant.log file. To the best of my knowledge all the met office sensors I’ve configured are working as expected.

2019-03-17 10:54:48 ERROR (MainThread) [homeassistant.core] Error doing job: Task exception was never retrieved
Traceback (most recent call last):
  File "/home/kdm/homeassistant/lib/python3.6/site-packages/homeassistant/helpers/entity.py", line 240, in async_update_ha_state
    device_attr = self.device_state_attributes
  File "/home/kdm/homeassistant/lib/python3.6/site-packages/homeassistant/components/sensor/metoffice.py", line 166, in device_state_attributes
    attr[ATTR_LAST_UPDATE] = self.data.data.date
AttributeError: 'NoneType' object has no attribute 'date'

Does it mean anything to anyone? Does it look like a buglet in HA?