[SOLVED] JupyterLab: Failed to load model class 'HBoxModel'

JupyterLab: Failed to load model class 'HBoxModel'

I am using JupyterLab and trying to run tqdm. I've had an error persist for quite a while that seems to be a JS error.

Extensions:

Other labextensions (built into JupyterLab)
   app dir: /opt/homebrew/Cellar/python@3.9/3.9.10/Frameworks/Python.framework/Versions/3.9/share/jupyter/lab
        @jupyter-widgets/jupyterlab-manager v5.0.3 enabled OK
        jupyter-leaflet v0.17.2 enabled OK

Error Message:

Failed to load model class 'VBoxModel' from module '@jupyter-widgets/controls'
Error: Module @jupyter-widgets/controls, version ^1.5.0 is not registered, however, 2.0.0 is

I have tried, re-installing, re-building all of the extensions listed above to no avail.

Solution

I had the same issue when upgrading to jupyterlab==3.6.3.

After upgrading ipywidgets to the at that time latest version 8.0.6, it still failed. I managed to fix the issue by downgrading then to ipywidgets==7.7.5.