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  • Post last modified:March 27, 2024
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How to solve JupyterLab Error – JupyterLab application assets not found in “/opt/homebrew/Cellar/[email protected]/3.11.6/Frameworks/Python.framework/Versions/3.11/share/jupyter/lab”

There are two solutions to solve the JupyterLab application assets not found issue first, build the Jupyter lab, and second change app-dir to point to the right application directory. Let’s look at these two solutions in detail.

Solution 1: Rebuild Assets & Extensions

Since you are getting JupyterLab application assets not found, you can build Jupyter Lab to find the assets. Running a build is typically necessary after installing new extensions or making changes to your JupyterLab configuration. It ensures that the environment is up to date and that any modifications you’ve made are reflected in the application.

JupyterLab application assets not found

The build command is used to build or rebuild the assets and extensions of JupyterLab. When you run jupyter lab build, it performs the following tasks:

  • Generate Configuration Files: It generates or updates the configuration files that control the behavior of JupyterLab. These files may include settings for extensions, appearance, keyboard shortcuts, and other customization options.
  • Build Extensions: If you have JupyterLab extensions installed, the build command may build or rebuild them. Extensions are additional functionalities or components that can be added to JupyterLab, such as new widgets, data visualization tools, or integrations with other libraries.
  • Generate Assets Manifest: JupyterLab generates a JSON manifest file that contains information about the assets (JavaScript, CSS, etc.) and extensions required for running JupyterLab.

Keep in mind that depending on your configuration, building JupyterLab can be a resource-intensive task, especially if you have a large number of extensions. It may take some time to complete, so be patient while it compiles and bundles the necessary assets. After the build is complete, you can run jupyter lab to start the JupyterLab environment with the updated assets and extensions.

Solution 2: Change Application Directory

You can also solve JupyterLab application assets not found by changing the application directory. The command jupyter lab --app-dir /opt/homebrew/share/jupyter/lab is used to launch JupyterLab with a specified application directory.

jupyter lab --app-dir /opt/homebrew/share/jupyter/lab

Explanation of this command:

  • jupyter lab: This is the main command to start JupyterLab, which is a web-based interactive development environment for Jupyter notebooks, code, and data. It’s an advanced alternative to the classic Jupyter Notebook interface.
  • --app-dir /opt/homebrew/share/jupyter/lab: This part of the command specifies the application directory for JupyterLab. The application directory is the location where JupyterLab looks for its configuration files, settings, and extensions. By specifying this directory, you can control where JupyterLab should look for its configuration and extensions, rather than using the default locations.

Keep in mind that the exact path to the application directory may vary depending on your system and how JupyterLab was installed. The --app-dir option is typically used when you want to manage JupyterLab configurations and extensions in a non-standard location.


Setting up Jupyter Lab is the first step to working on machine learning projects however, sometimes you get issues while running Jupyter Lab and these issues take more time to resolve. I have come across this JupyterLab application assets not found issues while running Jupyter Lab hence I thought documenting this would help others.

Naveen Nelamali

Naveen Nelamali (NNK) is a Data Engineer with 20+ years of experience in transforming data into actionable insights. Over the years, He has honed his expertise in designing, implementing, and maintaining data pipelines with frameworks like Apache Spark, PySpark, Pandas, R, Hive and Machine Learning. Naveen journey in the field of data engineering has been a continuous learning, innovation, and a strong commitment to data integrity. In this blog, he shares his experiences with the data as he come across. Follow Naveen @ LinkedIn and Medium