[FIXED] Jupyter notebook cell stays busy (*) even after the execution is complete

Issue

The Jupyter/IPython notebook started acting a little strange for my Ubuntu (14.04) computer.

Usually, a cell in jupyter notebook becomes busy with an asterisk (*) symbol next to it when it is executed and as soon as the execution is busy, the execution sequence number is displayed to denote successful completion of whatever task which was in it.

Now, whenever I execute a cell, it remains busy with an asterisk next to it even after the execution is complete. Then, any other cell which is given for execution also gets an asterisk but with no progress. Only when the interrupt command is given the execution sequence number shows up and I can continue to run other cells (in the same odd way).

What is causing this odd behaviour and how to solve it? It didn't happen to me before over the last two years of use -- neither in Ubuntu or Mac.

Solution

The cause seems to be the variable explorer notebook extension. The Jupyter notebook works fine when this is disabled.

I've recently installed jupyter_contrib_nbextensions and started to use the variable explorer in it. However, it seems like this is what is causing the problem. I've turned it off using the nbextensions tab in the home tree. Now, the cell executions are back to normal.

Answered By - Ébe Isaac