jupyterhub spawn failed server at http //127.0.0.1

 How to fix jupyterhub spawn failed server at http //127.0.0.1

In my VM, I am using docker to run Jupyter.

How to fix this issue?

1. Login to your Jupyter hub docker container - docker exec -it jupyterhub bash

2. Install notebook - pip install notebook

Try to reload again, it works.