Callback channel throws AttributeError: 'NoneType' object has no attribute 'startswith'

Rasa Open Source version

2.8.11

Rasa SDK version

2.8.2

Rasa X version

No response

Python version

3.8

What operating system are you using?

Linux

What happened?

Sending a request to webhooks/callback/webhook throws the following exception in the rasa server logs:

2021-10-21 14:51:17 ERROR    rasa.core.channels.rest  - An exception occured while handling user message 'None'.
Traceback (most recent call last):
  File "/opt/venv/lib/python3.8/site-packages/rasa/core/channels/rest.py", line 120, in receive
    await on_new_message(
  File "/opt/venv/lib/python3.8/site-packages/rasa/core/channels/channel.py", line 89, in handler
    await app.agent.handle_message(message)
  File "/opt/venv/lib/python3.8/site-packages/rasa/core/agent.py", line 577, in handle_message
    return await processor.handle_message(message)
  File "/opt/venv/lib/python3.8/site-packages/rasa/core/processor.py", line 96, in handle_message
    tracker = await self.log_message(message, should_save_tracker=False)
  File "/opt/venv/lib/python3.8/site-packages/rasa/core/processor.py", line 327, in log_message
    await self._handle_message_with_tracker(message, tracker)
  File "/opt/venv/lib/python3.8/site-packages/rasa/core/processor.py", line 594, in _handle_message_with_tracker
    parse_data = await self.parse_message(message, tracker)
  File "/opt/venv/lib/python3.8/site-packages/rasa/core/processor.py", line 567, in parse_message
    if text.startswith(INTENT_MESSAGE_PREFIX):
AttributeError: 'NoneType' object has no attribute 'startswith'

Command / Request

1. Run rasa init
2. Enable the rest and callback channel in credentials.yml. Set the config for the callback channel to:
callback:
  url: http://localhost:5005/webhooks/rest/webhook
3. Run rasa train
4. Run rasa run --enable-api -vv
5. Run:
curl -X POST \
     -H "Content-Type: application/json" \
     -d '{"sender":"test_user", "message":"/greet"}' \
     http://localhost:5005/webhooks/callback/webhook

Relevant log output

2021-10-21 14:51:16 DEBUG    rasa.core.processor  - Received user message 'hello world' with intent '{'id': -9191520425337906859, 'name': 'greet', 'confidence': 0.8585400581359863}' and entities '[]'
2021-10-21 14:51:16 DEBUG    rasa.core.processor  - Logged UserUtterance - tracker now has 14 events.
2021-10-21 14:51:16 DEBUG    rasa.core.policies.memoization  - Current tracker state:
[state 0] user intent: greet | previous action name: action_listen
[state 1] user intent: greet | previous action name: utter_greet
[state 2] user intent: greet | previous action name: action_listen
[state 3] user intent: greet | previous action name: utter_greet
[state 4] user intent: greet | previous action name: action_listen
2021-10-21 14:51:16 DEBUG    rasa.core.policies.memoization  - There is no memorised next action
2021-10-21 14:51:17 DEBUG    rasa.core.policies.ted_policy  - TED predicted 'utter_greet' based on user intent.
2021-10-21 14:51:17 DEBUG    rasa.core.policies.rule_policy  - Current tracker state:
[state 1] user intent: greet | previous action name: action_listen
[state 2] user intent: greet | previous action name: utter_greet
[state 3] user intent: greet | previous action name: action_listen
[state 4] user intent: greet | previous action name: utter_greet
[state 5] user text: hello world | previous action name: action_listen
2021-10-21 14:51:17 DEBUG    rasa.core.policies.rule_policy  - There is no applicable rule.
2021-10-21 14:51:17 DEBUG    rasa.core.policies.rule_policy  - Current tracker state:
[state 1] user intent: greet | previous action name: action_listen
[state 2] user intent: greet | previous action name: utter_greet
[state 3] user intent: greet | previous action name: action_listen
[state 4] user intent: greet | previous action name: utter_greet
[state 5] user intent: greet | previous action name: action_listen
2021-10-21 14:51:17 DEBUG    rasa.core.policies.rule_policy  - There is a rule for the next action 'utter_greet'.
2021-10-21 14:51:17 DEBUG    rasa.core.policies.ensemble  - Made prediction using user intent.
2021-10-21 14:51:17 DEBUG    rasa.core.policies.ensemble  - Added `DefinePrevUserUtteredFeaturization(False)` event.
2021-10-21 14:51:17 DEBUG    rasa.core.policies.ensemble  - Predicted next action using policy_2_RulePolicy.
2021-10-21 14:51:17 DEBUG    rasa.core.processor  - Predicted next action 'utter_greet' with confidence 1.00.
2021-10-21 14:51:17 DEBUG    rasa.core.processor  - Policy prediction ended with events '[<rasa.shared.core.events.DefinePrevUserUtteredFeaturization object at 0x7f77f458c8e0>]'.
2021-10-21 14:51:17 DEBUG    rasa.core.processor  - Action 'utter_greet' ended with events '[BotUttered('Hey! How are you?', {"elements": null, "quick_replies": null, "buttons": null, "attachment": null, "image": null, "custom": null}, {"utter_action": "utter_greet"}, 1634827877.2163692)]'.
2021-10-21 14:51:17 DEBUG    rasa.core.lock_store  - Issuing ticket for conversation 'default'.
2021-10-21 14:51:17 DEBUG    rasa.core.lock_store  - Acquiring lock for conversation 'default'.
2021-10-21 14:51:17 DEBUG    rasa.core.lock_store  - Acquired lock for conversation 'default'.
2021-10-21 14:51:17 DEBUG    rasa.core.tracker_store  - Recreating tracker for id 'default'
2021-10-21 14:51:17 DEBUG    rasa.core.processor  - Starting a new session for conversation ID 'default'.
2021-10-21 14:51:17 DEBUG    rasa.core.processor  - Policy prediction ended with events '[]'.
2021-10-21 14:51:17 DEBUG    rasa.core.processor  - Action 'action_session_start' ended with events '[<rasa.shared.core.events.SessionStarted object at 0x7f76f7e63760>, ActionExecuted(action: action_listen, policy: None, confidence: None)]'.
2021-10-21 14:51:17 DEBUG    rasa.core.processor  - Current slot values: 
        session_started_metadata: None
2021-10-21 14:51:17 DEBUG    rasa.core.lock_store  - Deleted lock for conversation 'default'.
2021-10-21 14:51:17 ERROR    rasa.core.channels.rest  - An exception occured while handling user message 'None'.
Traceback (most recent call last):
  File "/opt/venv/lib/python3.8/site-packages/rasa/core/channels/rest.py", line 120, in receive
    await on_new_message(
  File "/opt/venv/lib/python3.8/site-packages/rasa/core/channels/channel.py", line 89, in handler
    await app.agent.handle_message(message)
  File "/opt/venv/lib/python3.8/site-packages/rasa/core/agent.py", line 577, in handle_message
    return await processor.handle_message(message)
  File "/opt/venv/lib/python3.8/site-packages/rasa/core/processor.py", line 96, in handle_message
    tracker = await self.log_message(message, should_save_tracker=False)
  File "/opt/venv/lib/python3.8/site-packages/rasa/core/processor.py", line 327, in log_message
    await self._handle_message_with_tracker(message, tracker)
  File "/opt/venv/lib/python3.8/site-packages/rasa/core/processor.py", line 594, in _handle_message_with_tracker
    parse_data = await self.parse_message(message, tracker)
  File "/opt/venv/lib/python3.8/site-packages/rasa/core/processor.py", line 567, in parse_message
    if text.startswith(INTENT_MESSAGE_PREFIX):
AttributeError: 'NoneType' object has no attribute 'startswith'

Definition of done

• Investigate issue
• Fix bug if straightforward
• Otherwise: Create issue for problem if it is too complicated

[tayfun]

Could be related to https://github.com/RasaHQ/rasa/issues/10504 ?

[hsm207]

@carlad and I had a call and agreed that setting:

callback:
  url: http://localhost:5005/webhooks/rest/webhook

is a usage error.

The smart device should send the notification directly to the input/output channel.