Telegram_bot throws an error when sending command

Folks,
I do have in my notify.yaml

  •   - name: telegram_ihaus
        platform: telegram
        api_key: <api_key>
        chat_id: <chat-id>
    

configuration.yaml

telegram_bot:
      - platform: polling
        api_key: <api-token>
        allowed_chat_ids: 
          - <chat-id>

Action in it’s own yaml file

alias: 'Telegram bot that reply pong to ping'
hide_entity: true
trigger:
  platform: event
  event_type: telegram_command
  event_data:
    command: '/ping'
action:
  - service: notify.telegram_ihaus
    data:
      message: 'pong' 

When I send my bot a message like “/ping” I do get an error and nothing happens:

Sep 25 19:24:17 home-assistant hass[710]: 2017-09-25 19:24:17 ERROR (MainThread) [homeassistant.components.telegram_bot] Incoming message is not allowed ({'date': 1506360257, **'text': '/ping'**, 'entities': [{'type': 'bot_command', 'offset': 0, 'length': 5}], 'message_id': 10, 'from': {'is_bot': False, 'language_code': 'de-DE', 'id': 289103473, 'username': 'mindelheimer_bua', 'last_name': 'Schubert', 'first_name': 'Juergen'}, 'chat': {'id': <xxxxid>, 'type': 'private', 'last_name': 'lastname', 'username': 'right username', 'first_name': 'firstname'}})

no reaction. What went wrong?