# Action\_default\_fallback already defined

**URL:** https://forum.rasa.com/t/action-default-fallback-already-defined/629
**Category:** Rasa Open Source
**Created:** [August 23, 2018, 11:40am UTC](https://forum.rasa.com/t/action-default-fallback-already-defined/629 "2018-08-23T11:40:46Z")
**Posts on this page:** 1
**Showing post:** 1

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### Author: ![Krogsager](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.rasa.com/krogsager/32/95_2.png) [@Krogsager](https://forum.rasa.com/u/Krogsager)
#### Post date: [August 23, 2018, 11:40am UTC](https://forum.rasa.com/t/action-default-fallback-already-defined/629/1 "2018-08-23T11:40:47Z")

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**Fixed/hack/work-around** : I don’t think this is the right approach but I got the fallback to work. I modified **rasa\_core.train** to suport a new argument, in short:

```
   fallback = FallbackPolicy(core_threshold=fallback_threshold,
                                    nlu_threshold=fallback_threshold)

        policies.append(fallback)
    

    agent = Agent(domain_file, policies)

```

**domain.yml**

```
templates:
  utter_default:  
    - "You are speaking nonsense my friend"

```

I start the training with:

> python -m rasa\_core.train -d domain.yml -s “$STORY” -o models/current/dialogue --epochs 120 --fallback 0.3

**Edit** : So I came across ´ActionDefaultFallback´ in the changelog, and found ´utter\_default´ in the documentation. But when I add ´utter\_default´ to my domain.yml, there still isn’t any fallback in the bot. What else do I need to set up for the default fallback to work?

I want to define a default fallback action `action_default_fallback` but I get the error when I run `rasa_core.train`

> ValueError: Action names are not unique! Found two actions with name ‘action\_default\_fallback’. Either rename or remove one of them.

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