Hi @urbanusm !
Thanks for providing the code! I was able to reproduce and by googling the error I’ve found this stack-overflow post that suggests to pip install websockets==10.0, so I added ADD pip install websockets==10.0 and it did the trick
This is not the full solution though, as I’m now hitting some other error like ModuleNotFoundError: No module named 'actions'. I think this is due to the Dockerfile not copying anything like source files or requirements.txt for dependencies
I suggest you research more about Build your Python image and what files does rasa actually need, since there’s where these errors arise