Jupyter notebook blank page on start up

Hi,

I have a very similar problem as the one explained in ##4503.

When I launch jupyter, I get a blank page with url: http://localhost:8888/treehttp://localhost:8888/tree

No Dashboard, to listing of current directory.
Just a blank page.

The solution in #4503, with "uninstalling notebook and pip install notebook==5.7.5“ does not help me and I still see the blank page, when running „Jupyter notebook“.

I am using a virtual environment using python==3.6, crated by Conda (miniconda3) on a linux (Debian) virtual machines which is running on top of MacOs Catalina (version 10.15.7).

No source file or test is named. Start by reproducing the launch with the reported Python 3.6 Conda environment on Debian, inspect the generated URL and compare the behavior with issue #4503. Done means the Jupyter launch opens the dashboard and directory listing instead of a blank page.

Written by the indexing model from the issue text.