Rasa 2.0 training files

The only difference from a working file, and a file that throughs an error is this nlu: at the second line:

version: "2.0"
nlu: # Do not remove, else rasa will ignore the file...

stories:

##
## Form: Departure
##
- story: flight departure information - unhappy path - stop - el

If I delete this line, I get the error above. I am not sure if this error is generated without --debug in rasa train. (I always use it).

I think there must be something strange in your rasa environment, because that I cannot reproduce. If I do:

pip install rasa==2.0.0
rasa init
rasa train --debug
rasa shell

Everything is working without any changes to the data files.