I am having the exact problem with the notify messaging and it is not working despite all the suggestions:
action:
- service: notify.notify
data:
messsage: Attempting to arm system when door is open
title: Alarm
mode: single
–
File “C:\Users\rsiva\Documents\Hass\HassWP_2021.1.1\python-3.8.7\lib\site-packages\voluptuous\schema_builder.py”, line 432, in validate_mapping
raise er.MultipleInvalid(errors)
voluptuous.error.MultipleInvalid: extra keys not allowed @ data[‘messsage’]
Thanks
rsiva-tech