title: Rasa custom actions events are lost
body: <p>I'm trying to implement custom actions and have added action_get_answer to <strong>domain.yml.</strong></p>
  
  <pre><code>actions:
   - utter_greet
   - utter_cheer_up
   - utter_did_that_help
   - utter_happy
   - utter_goodbye
   - actions.GetAnswer
  </code></pre>
  
  <p>Added the action in <strong>actions.py</strong> :</p>
  
  <pre><code>class GetAnswer(Action):
  
      def name(self) -&gt; Text:
          return "action_get_answer"
  
  
      def run(self, dispatcher: CollectingDispatcher,
              tracker: Tracker,
              domain: Dict[Text, Any]) -&gt; List[Dict[Text, Any]]:
  
          dispatcher.utter_message("action_get_answer")
  
          return []
  </code></pre>
  
  <p>Ran the action server: </p>
  
  <p><code>$ rasa run actions</code></p>
  
  <p>Upon running rasa server : </p>
  
  <p><code>$ rasa x</code></p>
  
  <p>i get this error and <code>GetAnswer</code> is not triggered -</p>
  
  <blockquote>
    <p>ERROR rasa.core.processor - Encountered an exception while running
    action 'action_get_answer'. Bot will continue, but the actions events
    are lost. Make sure to fix the exception in your custom code.</p>
  </blockquote>
  
  <p>How do I make this work?</p>
  
  <p>Thanks</p>