title: jupyter notebook running issues
body: <p>I am running some python code using a jupyter notebook. The notebook should take a couple of days to finish. After a couple of running hours a massage is shown: &quot;Error rendering Jupyter widget: missing widget manager.&quot; The hourglass at the chrome tab keeps on running, but the * symbol next to the cell no longer appears, only [] is appeared. I have two questions: 1. is the notebook still running? 2. How can I fix this?</p>