Utter_button_message on basic rasa example not working

I have tried your action in my action file and it worked totally fine. I have faced same kind of issue when using formaction. Check this out

But with custom actions it did not cause any issues so far. May be you should try restart action server again using rasa run actions --actions actions command and you can also refer the logs to find out what is happening inside. In case if you need to get the log file use rasa shell --log-file out.log --debug.