“Error displaying widget: model not found” with Jupyter Lab

I followed the pip installation instructions but get “Error displaying widget: model not found” in the lab. In the notebook it works fine. I tried to reinstall everything related but couldn’t get it to work. Is this a known issue?

Here are the version infos:

D:\dev>jupyter --version
jupyter core     : 4.7.1
jupyter-notebook : 6.2.0
qtconsole        : 5.0.2
ipython          : 7.20.0
ipykernel        : 5.4.3
jupyter client   : 6.1.11
jupyter lab      : 3.0.7
nbconvert        : 6.0.7
ipywidgets       : 7.6.3
nbformat         : 5.1.2
traitlets        : 5.0.5

D:\dev>jupyter nbextension list
Known nbextensions:
  config dir: c:\prog\python39\etc\jupyter\nbconfig
    notebook section
      jupyter-datawidgets/extension enabled
      - Validating: problems found:
        - require?  X jupyter-datawidgets/extension
      jupyter-matplotlib/extension enabled
      - Validating: ok
      k3d/extension enabled
      - Validating: ok
      jupyter-js-widgets/extension enabled
      - Validating: ok

D:\dev>jupyter nbextension list
Known nbextensions:
  config dir: c:\prog\python39\etc\jupyter\nbconfig
    notebook section
      jupyter-datawidgets/extension enabled
      - Validating: problems found:
        - require?  X jupyter-datawidgets/extension
      jupyter-matplotlib/extension enabled
      - Validating: ok
      k3d/extension enabled
      - Validating: ok
      jupyter-js-widgets/extension enabled
      - Validating: ok

D:\dev>jupyter labextension list
JupyterLab v3.0.7
        jupyter-matplotlib v0.8.3 enabled ok
        @jupyter-widgets/jupyterlab-manager v3.0.0 enabled ok (python, jupyterlab_widgets)

Other labextensions (built into JupyterLab)
        jupyterlab-datawidgets v7.0.0 enabled ok
        k3d v2.9.3 enabled ok

Uninstalled core extensions:
    @jupyter-widgets/jupyterlab-manager
    k3d

D:\dev>node --version
v14.15.5

[CagtayFabry]

are there any plans to update the extension to the new JupyterLab 3.x extension system? https://jupyterlab.readthedocs.io/en/stable/extension/extension_migration.html

This would also simplify installation for users

[cignoni]

After a quick cleanup of installed pythons (uninstalled all pip packages and removed all python brew casks, I started to use pyenv and this time I installed jupyterlab and k3d only locally and everything worked. Thanks for suggesting that the local global clash could be the source of all the evil…

Just for future memory this worked for me:

brew install pyenv
echo 'eval "$(pyenv init --path)"' >> ~/.zprofile\n
pyenv install 3.9.7
cd mypythonexperiments
pyenv local 3.9.7
pip install jupyterlab
pip install k3d
jupyter-lab

So I can continue to play with pymeshlab using k3d as viewer…

Thanks again!!