ERROR asyncio - Task exception was never retrieved after intent is selected for two stage fallback

Hi,

I was trying to implement my own two stage fallback and run into “ERROR asyncio - Task exception was never retrieve” after the user selects one of the buttons. Could someone help me figure out whats the issue here?

I implemented my two stage fallback following the rasa documentation. config.yml

- name: FallbackClassifier
  threshold: 0.5
  ambiguity_threshold: 0.1

and in rules.yml

- rule: Implementation of the Two-Stage-Fallback
  steps:
  - intent: nlu_fallback
  - action: action_two_stage_fallback
  - active_loop: action_two_stage_fallback

I have added ‘utter_ask_rephrase’ as well as an ultimate fallback in my domain.yml.

If the user selects the intent, here are the log messages I got from rasa shell:

? Did you mean 'anfahrt'? 1: Yes (/anfahrt)                                                                                          
2022-05-24 10:21:27 DEBUG    rasa.core.lock_store  - Issuing ticket for conversation '4c47803bd2d448ba9e57a37d03d168c5'.
2022-05-24 10:21:27 DEBUG    rasa.core.lock_store  - Acquiring lock for conversation '4c47803bd2d448ba9e57a37d03d168c5'.
2022-05-24 10:21:27 DEBUG    rasa.core.lock_store  - Acquired lock for conversation '4c47803bd2d448ba9e57a37d03d168c5'.
2022-05-24 10:21:27 DEBUG    rasa.core.tracker_store  - Recreating tracker for id '4c47803bd2d448ba9e57a37d03d168c5'
2022-05-24 10:21:27 DEBUG    rasa.engine.runner.dask  - Running graph with inputs: {'__message__': [<rasa.core.channels.channel.UserMessage object at 0x7efd01939460>]}, targets: ['run_RegexMessageHandler'] and ExecutionContext(model_id='40addd8389b14c4da300be8cde979728', should_add_diagnostic_data=False, is_finetuning=False, node_name=None).
2022-05-24 10:21:27 DEBUG    rasa.engine.graph  - Node 'nlu_message_converter' running 'NLUMessageConverter.convert_user_message'.
2022-05-24 10:21:27 DEBUG    rasa.engine.graph  - Node 'provide_SpacyNLP0' running 'SpacyNLP.provide'.
2022-05-24 10:21:27 DEBUG    rasa.engine.graph  - Node 'run_SpacyNLP0' running 'SpacyNLP.process'.
2022-05-24 10:21:27 DEBUG    rasa.engine.graph  - Node 'run_SpacyTokenizer1' running 'SpacyTokenizer.process'.
2022-05-24 10:21:27 DEBUG    rasa.engine.graph  - Node 'run_SpacyEntityExtractor2' running 'SpacyEntityExtractor.process'.
2022-05-24 10:21:27 DEBUG    rasa.engine.graph  - Node 'run_SpacyFeaturizer3' running 'SpacyFeaturizer.process'.
2022-05-24 10:21:27 DEBUG    rasa.engine.graph  - Node 'run_LexicalSyntacticFeaturizer4' running 'LexicalSyntacticFeaturizer.process'.
2022-05-24 10:21:27 DEBUG    rasa.engine.graph  - Node 'run_CountVectorsFeaturizer5' running 'CountVectorsFeaturizer.process'.
2022-05-24 10:21:27 DEBUG    rasa.engine.graph  - Node 'run_EntitySynonymMapper6' running 'EntitySynonymMapper.process'.
2022-05-24 10:21:27 DEBUG    rasa.engine.graph  - Node 'run_DucklingEntityExtractor7' running 'DucklingEntityExtractor.process'.
2022-05-24 10:21:27 DEBUG    urllib3.connectionpool  - Starting new HTTP connection (1): localhost:8000
2022-05-24 10:21:27 DEBUG    urllib3.connectionpool  - http://localhost:8000 "POST /parse HTTP/1.1" 200 None
2022-05-24 10:21:27 DEBUG    rasa.engine.graph  - Node 'run_EntitySynonymMapper8' running 'EntitySynonymMapper.process'.
2022-05-24 10:21:27 DEBUG    rasa.engine.graph  - Node 'run_DIETClassifier9' running 'DIETClassifier.process'.
2022-05-24 10:21:27 DEBUG    rasa.engine.graph  - Node 'run_FallbackClassifier10' running 'FallbackClassifier.process'.
2022-05-24 10:21:27 DEBUG    rasa.nlu.classifiers.fallback_classifier  - NLU confidence 0.31356197595596313 for intent 'fuehrung_schulklasse' is lower than NLU threshold 0.50.
2022-05-24 10:21:27 DEBUG    rasa.engine.graph  - Node 'run_RegexFeaturizer11' running 'RegexFeaturizer.process'.
2022-05-24 10:21:27 DEBUG    rasa.engine.graph  - Node 'domain_provider' running 'DomainProvider.provide_inference'.
2022-05-24 10:21:27 DEBUG    rasa.engine.graph  - Node 'run_RegexMessageHandler' running 'RegexMessageHandler.process'.
2022-05-24 10:21:27 DEBUG    rasa.core.processor  - Received user message '/anfahrt' with intent '{'name': 'anfahrt', 'confidence': 1.0}' and entities '[]'
2022-05-24 10:21:27 DEBUG    rasa.core.processor  - Logged UserUtterance - tracker now has 10 events.
2022-05-24 10:21:27 DEBUG    rasa.core.lock_store  - Deleted lock for conversation '4c47803bd2d448ba9e57a37d03d168c5'.
2022-05-24 10:21:38 ERROR    asyncio  - Task exception was never retrieved

If the user selects “something else” and rasa should ask the user to reformulate the question:

rasa.core.processor  - Received user message '/trigger_rephrase' with intent '{'name': 'nlu_fallback', 'confidence': 0.5}' and entities '[]'
2022-05-24 09:59:26 DEBUG    rasa.core.processor  - Logged UserUtterance - tracker now has 17 events.
2022-05-24 09:59:26 DEBUG    rasa.core.lock_store  - Deleted lock for conversation '542c55763b354bbf9ed0d20d7a80982c'.
2022-05-24 09:59:36 ERROR    asyncio  - Task exception was never retrieved