2021-01-11 AttributeError: module ‘nbconvert.exporters’ has no attribute ‘WebPDFExporter’

I faced the following issue when running a notebook server juste the installation.

AttributeError: module 'nbconvert.exporters' has no attribute 'WebPDFExporter'

That leaded to an empty screen showing “500: internal error” returned by the server. I could not find a solution despite many searches on the internet so I decided to modify the code of notebook in file notebook/handler.py and update with the following lines:

    exporter_class = get_exporter(name)
except AttributeError:

I hope this issue if fixed next time I install it. I remember facing the same one quite a while but I have no memory on how I got it fixed.