Jupyter notebook kernel not connecting

Question

I have previously used Jupyter Notebook (python 2 and 3) on my mac. After not using it for a while, there seems to be a problem I am unable to fix. When startin

Answer 1

Running the following version of jupyter and tornado seemed to solve the issue:

Jupyter: 4.4.0

Tornado: 4.5.3

I needed to downgrade my version of tornado (which was 5.0.2)