Error in log:

Can rhey help me?

Logger: homeassistant
Source: components/sensor/significant_change.py:38
First occurred: 7:36:26 (4 occurrences)
Last logged: 8:46:49

Error doing job: Task exception was never retrieved
Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/components/alexa/state_report.py", line 93, in async_entity_state_listener
    if not checker.async_is_significant_change(
  File "/usr/src/homeassistant/homeassistant/helpers/significant_change.py", line 175, in async_is_significant_change
    result = check_significantly_changed(
  File "/usr/src/homeassistant/homeassistant/components/sensor/significant_change.py", line 38, in async_check_significant_change
    new_value = float(new_state)
ValueError: could not convert string to float: 'None'