I faced same issue and was able to solve it by doing a proper presentation of S_INFO widget, as described in sample sketch: https://www.home-assistant.io/integrations/notify.mysensors/
The error message is quite misleading.
I faced same issue and was able to solve it by doing a proper presentation of S_INFO widget, as described in sample sketch: https://www.home-assistant.io/integrations/notify.mysensors/
The error message is quite misleading.