pythonic2020

``` AssertionError [I 04:11:31.982 NotebookApp] Starting buffering for 17a5fa29-bfdb-4a64-9b5c-03f2051ce9b8:f23f5821d4cd48d8a8ee97b5bed74ea2 Task exception was never retrieved future: Traceback (most recent call last): File "C:\Users\me\Miniconda3\envs\forge39\lib\site-packages\tornado\websocket.py", line 1092, in wrapper await fut tornado.iostream.StreamClosedError: Stream...

If I create a new, fresh conda-forge based Python 3.9 env and install just matplotlib, notebook, and ipympl (and required dependencies), the issue still occurs.

Your IntSlider code above works perfectly in a classic notebook. Env creation: ``` conda create -n ipympl39 -c conda-forge python=3.9 conda activate ipympl39 conda config --env --set channel_priority flexible conda...

I tried the 3d code in my new env in a classic notebook in MS Edge, and got these Jupyter terminal errors. Note "**AttributeError: 'NoneType' object has no attribute 'advance'**"....

Using notebook 7.0.0, ipympl works fine!

ipympl 0.9.3 works fine in notebook 6.5.5 in a python 3.9.17 environment! "Case" closed. :-)