Try upgrading jupyter hub first:
pip install --upgrade jupyterhub
pip install --upgrade --user nbconvert
If you are inside a conda environment, run the following command instead.
conda install nbconvert==5.4.1
Try upgrading jupyter hub first:
pip install --upgrade jupyterhub
pip install --upgrade --user nbconvert
If you are inside a conda environment, run the following command instead.
conda install nbconvert==5.4.1