I also had to downgrade the Jupyter extension to version 2025.6 instead of 2025.7. I have VS Code version 1.103.2 on macOS. After that, the list of Python Environments was loading correctly.
Answer from schneeb on Stack OverflowI also had to downgrade the Jupyter extension to version 2025.6 instead of 2025.7. I have VS Code version 1.103.2 on macOS. After that, the list of Python Environments was loading correctly.
For example I have "Extension" named Python in the image below that gets updated or installed by vsCode automatically
- You have to wait for the "Extensions" to be installed.
- Make sure you have an internet connection.
- make sure you have a fast internet connection so that it can be installed faster.
- After installation restart "vsCode"
If it doesn't work for you, try uninstalling the extension and reinstalling it
This is all I know and it happened to me
Here is my package.json
Whatever I do it doesn't work on the published version. When I start the "Start Debugging (F5)" from vscode it correctly triggers the activate method exported in my extention.js file!
But when it is published only my declared grammar works
I've watched other source's code and I feel like I do things correctly but VSCode just doesn't want to
Please help!
Hey everyone,
I'm running into a persistent issue with the Jupyter extension in VS Code and I'm hoping someone can point me in the right direction.
I'm trying to run a simple Python cell in a .ipynb notebook, but I can't execute anything because the Jupyter extension fails to start. As you can see in the screenshot, I keep getting the error notification: Extension activation failed, run the 'Developer: Toggle Developer Tools' command for more information.
What I've Tried So Far:
-
Reinstalling: I have completely uninstalled and reinstalled the Jupyter extension (and its related dependencies like the Python extension) multiple times.
-
Restarts: I have closed and reopened VS Code, and even restarted my computer.
-
New Environments: I've created fresh virtual environments (using
venv) and installedipykernelwithin them, but the issue persists no matter which interpreter I select. -
Different Files: This happens with any notebook file, even a brand new one with a single
print()statement.
I feel like I'm missing something obvious, but I can't figure out what
Hello, I am trying to download the Python extension from Microsoft and it's not working, I am getting this error:
Extension activation failed, run the 'Developer: Toggle Developer Tools' command for more information.
Additionally at the bottom, the spinning "Python extension loading..." just never finishes loading. I'm trying to debug my code and can't, can anyone help? Thank you !
I fix it doing a complete uninstall of VS Code:
Use the uninstall: "%USERPROFILE%/AppData/Local/Programs/Microsoft VS Code/uninst000.exe"
Delete directory "%USERPROFILE%/AppData/Roaming/Code"
Delete directory "%USERPROFILE%/.vscode"
Source: Uninstall visual studio code in windows
For me, the solution was to run a profile on the extension host
The profile will probably get stuck, so I cancelled it by clicking on the profiling task in the status bar at the bottom of VS Code, and then saw that the profile had got stuck on a single extension. You can check this by running > Developer: Show Running Extensions in the command palette.
I uninstalled that extension, restarted the extension host, and all was resolved.
The extension causing issues for me was danilopolani.yet-another-phpunit
I'm trying to open and execute some ipynb files in Code on Arch Linux. Installed Python and Jupyter extensions.
Whenever I try to run code in the ipnyb file, I get this nagging error message for the Jupyter extension saying
Extension activation failed, run the 'Developer: Toggle Developer Tools' command for more information.
I tried switching the interpreter to the default Python 3.10.2 and also the Python 3.9.x installation in the Anaconda custom environment, but still no luck. Any idea how to fix this?
I had the same issue (at least it seemed the same), however it is possible to work around it if you are using the Python extension in conjunction with Remote Debugging.
You can ignore the extension's activation failure if that is your primary use, since VSCode is still able to debug remotely using Python Remote Attach.
After some more work on this, I found that updating the Python Extension to the pre-release version cleared up the various errors that came with the recent updates.
You could roll back to the historical version in the extension store to solve this problem.
If you want, you can also follow this issue on github, it's the same problem.
