问题
Currently, a jupyter notebook does not show the lateral table of contents. All the other notebooks do. In fact, for that notebook under menu->edit the nbextensions config disappeared, so, it looks like that notebook does not load the extension.
My jupyter version is 4.4.0.
How to fix that notebook?
回答1:
Apparently, all it needs is to shutdown the notebook. After restarting it, all works fine. I suppose that problem happens when the notebook has been closed wrongly without the proper "close and halt" procedure.
来源：https://stackoverflow.com/questions/55065406/table-of-contents-disappeared-in-jupyter-notebook