Jupyter notebook service error

Problem background

I created a CONDA virtual environment of Python 3.8 and prepared to install Jupiter notebook in this virtual environment. Start Jupiter notebook in CMD to pop up the browser and working interface smoothly. However, when creating a new IPython file, the kernel always shows that it is busy and cannot run the script in the cell.

reason

Through searching for information, I found that most of the reasons on the Internet were attributed to the mismatch between ipykernal and pyzmq versions. For this purpose, I refer to another virtual environment I created earlier. The jupyter notebook in this environment can run normally, and its corresponding versions are ipykernal 6.2.0 and pyzmq 19.0.2 respectively

Solution:

pip install ipykernal=6.2.0
pip install pyzmq=19.0.2