After the upgrade to Ubuntu 22.04 Jupyter Notebook (on Firefox 99.0.1) would greet me with an Access Denied error. Not exactly conducive to work.
I tried setting access right of the directories (I also thought about access issues given that .local is a hidden directory), but it turns out that creating an explicit configuration helps:
jupyter notebook --generate-config
This creates a file at: ~/.jupyter/jupyter_notebook_config.py
and in this (text) file we’re looking for c.NotebookApp.use_redirect_file, uncomment it, and set it to
c.NotebookApp.use_redirect_file = False
(as explained in the comments; this seems completely fine on a single-user machine).