Error adding entities for domain sensor with platform meteoalarm_m

[ercsey]

Since couple of weeks sometimes it gives error during HA start. The strange thing is that this not happens every time.
I'm using Home Assistant Supervised v2021.2.3 under Debian GNU/Linux 10 (buster).
These are the error messages:

1. Setup of sensor platform meteoalarm_m is taking over 10 seconds.
2. Setup of platform meteoalarm_m is taking longer than 60 seconds. Startup will proceed without waiting any longer.

Error adding entities for domain sensor with platform meteoalarm_m Traceback (most recent call last): File "/usr/src/homeassistant/homeassistant/helpers/entity_platform.py", line 315, in async_add_entities await asyncio.gather(*tasks) File "/usr/src/homeassistant/homeassistant/helpers/entity_platform.py", line 506, in _async_add_entity await entity.add_to_platform_finish() File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 531, in add_to_platform_finish self.async_write_ha_state() File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 296, in async_write_ha_state self._async_write_ha_state() File "/usr/src/homeassistant/homeassistant/helpers/entity.py", line 320, in _async_write_ha_state sstate = self.state File "/config/custom_components/meteoalarm_m/sensor.py", line 134, in state return str(self._data['count']) TypeError: 'NoneType' object is not subscriptable

Please let me know if you need further information and sorry is it's false alarm.
Thank you.