JupyterLab build is suggested and successfully installed, but will not work. Why?

Question

I'm running JupyterLab from Anaconda, and installed a JupyterLab plotly extension using:

conda install -c conda-forge jupyterlab-plotly-extension

Apparently, the installation was successful, but something is still wrong. When launching JuyterLab, I'm getting this prompt:

Clicking BUILD gives me this:

And clicking RELOAD relods JupyterLab, BUT I'm getting this again:

And on and on it spins. Does anyone know why?

Clicking CANCEL does not help either because plotly won't produce any plots, only blank spaces:

Answer 1

Solution:

Deactivate firewall and run the following command in a windows command prompt:

jupyter lab build

---

The details:

This turned out to be a firewall problem, and I'm not sure why it would not be prompted as such in the JupyterLab interface. The following command in a windows command prompt returned the error message below:

Command:

jupyter lab build

Output:

C:>jupyter labextension list JupyterLab v0.34.9 Known labextensions: app dir: C:\Users*******\AppData\Local\Continuum\anaconda3\share\jupyter\lab @jupyterlab/plotly-extension v0.18.2 enabled ok

Build recommended, please run jupyter lab build: @jupyterlab/plotly-extension needs to be included in build

C:>jupyter lab build [LabBuildApp] JupyterLab 0.34.9 [LabBuildApp] Building in C:\Users*******\AppData\Local\Continuum\anaconda3\share\jupyter\lab [LabBuildApp] > node C:\Users*******\AppData\Local\Continuum\anaconda3\lib\site-packages\jupyterlab\staging\yarn.js install yarn install v1.9.4 info No lockfile found. [1/4] Resolving packages... error An unexpected error occurred: "https://registry.yarnpkg.com/@jupyterlab%2fapplication: self signed certificate in certificate chain". info If you think this is a bug, please open a bug report with the information provided in "C:\Users\*******\AppData\Local\Continuum\anaconda3\share\jupyter\lab\staging\yarn-error.log".

What pointed me towards suspecting a firewall problem was this part:

self signed certificate in certificate chain

Running the same command on less rigid fire-wall settings triggers this output (shortened):

WARNING in d3-array Multiple versions of d3-array found: 1.2.4 ./~/d3-scale/~/d3-array from ./~/d3-scale/~/d3-array\src\index.js 2.2.0 ./~/d3-array from ./~/d3-array\src\index.js

Check how you can resolve duplicate packages: https://github.com/darrenscerri/duplicate-package-checker-webpack-plugin#resolving-duplicate-packages-in-your-bundle

Child html-webpack-plugin for "index.html": 1 asset Entrypoint undefined = index.html [KTNU] ./node_modules/html-loader!./templates/partial.html 567 bytes {0} [built] [YuTi] (webpack)/buildin/module.js 497 bytes {0} [built] [aS2v] ./node_modules/html-webpack-plugin/lib/loader.js!./templates/template.html 1.22 KiB {0} [built] [yLpj] (webpack)/buildin/global.js 489 bytes {0} [built] + 1 hidden module

And despite some warning messages, JupyterLab now produces plotly figures without any problems: