PyQt5.QtWebKitWidgets error in Spyder

Problem: Spyder cannot open and gives an error ModuleNotFoundError: No module named 'PyQt5.QtWebKitWidgets'

Cause: The problem seems to be due to inconsistencies in where the package PyQt is located in the Anaconda environments. Can be due to using pip to install into an Anaconda environment (maybe). Might also be due to outdated versions of the package PyQtor PyQt5.

Solution: In lack of a better solution, I removed the entirety of my Anaconda environment and created it again from scratch. If anybody has a better or simpler solution please add it!

In this example, I create the environment by reinstalling MNE from the source. In other cases where the environment is not defined elsewhere, you might want to backup the environment into a text file. Like this: conda env export > environment.yaml

1) Remove old environment

conda env remove --name mne

2) Create new environment (from MNE)

conda install --channel=conda-forge --name=base mamba
mamba create --override-channels --channel=conda-forge --name=mne mne

For more information on installing MNE, see here: https://mne.tools/stable/install/manual_install.html

3 Reinstall Spyder

mamba install spyder