Capo_Mestre:

Is there anything else I can do to get it working on my machine?


It seems Jupyter is again failing, while Spyder seems to work?
If that’s the case, your best option would be to try to come up with a small multiprocessing example and file an issue against Jupyer. I’m not sure, if there is much more you can do, as the issue sounds like a bad interaction in the notebook with multiprocessing.
The numpy warning points towards a nested array with variable lengths. Could you check, where this warning is created and try to fix it? I don’t think it’s related to the issue you are seeing, but might be worth a try.