For no particular reason, I've got « RuntimeError: This event loop is already running » when starting Jupyter IPython. I was stucked, unable to run any IPython Notebook. Note that I'm not using Anaconda.
It was probably after updating one library of the Python machine learning ecosystem (Scipy, NumPy, matplotlib, scikit-learn, pandas, Keras, ...) but I cannot remember which one.
I've tried to upgrade the usual suspects, tornado and ipykernel, with no success. Furthermore I'm not using any fancy thing like asyncio in my own code.