Jupyter Notebook

[Dixon]

Suddenly I'm having a problem starting Jupyter Notebook, or should I say starting Python 3 in Notebook. Something is blocking it, whether it's Norton or Windows I don't know. I called Norton, and was told that I need to re-install Windows 10, as the os is corrupted. Then they generously offered to sell me the service of fixing my issue. I politely declined, as all other applications seem to be running just dandy.

[Larz60+]

I'm so glad I use Linux.
On the serious side, have you changed something?
perhaps started a virtual environment?
also, please show the full unaltered error traceback.