Adding platform: time_date shows check_circle?

Hi,

I’m new to hass.io and try to make the first views. So I try to show the Date and Time at my first page but if I add

sensor:
  - platform: time_date
    display_options:
      - 'time'
      - 'date'
      - 'date_time'
      - 'date_time_iso'
      - 'time_date'
      - 'time_utc'
      - 'beat'

To my Configuration.yaml. It shows Check_circle and I can not save the file. Whats wrong here?

Thanks, Steffen