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.
Answer from Zachary Barnett on Stack OverflowI 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.
Unable to debugger for python , it says "Extension activation failed, run the 'Developer: Toggle Developer Tools' command for more information."
visual studio code - How would I fix the issue of the python extension loading and Extension activation failed messages appearing? - Stack Overflow
visual studio code - Python "Extension activation failed, run the 'Developer: Toggle Developer Tools' command for more information" - Stack Overflow
Extension activation failed, run the 'Developer: Toggle Developer Tools' command for more information.
I had this same issue and finally got it fixed!
If you are on an Linux and are using an Arch-based distro with AUR support, simply install the code-features package using:
yay -S code-features
or any AUR helper of your choosing.
On other operating systems, you should do the following:
Open your VSCode's product.json. I do not know where this file is on your operating system, so please do some research.
Look for the following line:
"extensionAllowedProposedApi": [ ...
Add the following entry to that array:
"ms-toolsai.jupyter": ["notebookConcatTextDocument",
"notebookControllerKind", "notebookDebugOptions", "notebookDeprecated",
"notebookEditor", "notebookEditorDecorationType", "notebookEditorEdit",
"notebookMessaging", "notebookMime", "notebookCellExecutionState",
"portsAttributes", "textDocumentNotebook", "quickPickSortByLabel"]
For example, if the line was originally:
"extensionAllowedProposedApi": [ "extension1", "extension2" ]
Then change it to:
"extensionAllowedProposedApi": [ "extension1", "extension2",
"ms-toolsai.jupyter": ["notebookConcatTextDocument",
"notebookControllerKind", "notebookDebugOptions", "notebookDeprecated",
"notebookEditor", "notebookEditorDecorationType", "notebookEditorEdit",
"notebookMessaging", "notebookMime", "notebookCellExecutionState",
"portsAttributes", "textDocumentNotebook", "quickPickSortByLabel"] ]
Note that with the second method, you will need to edit product.json every time you update VSCode.
Just ran into this today (I'm on MacOS for my work computer). In my case, upgrading to the pre-release version of the Jupyter extension (v2022.5.1001281006) solved it right away.
If you're not an experienced programmer/software engineer, as is the case for me, I suggest trying to upgrade (or roll back) either VS code or the plugin itself before going with your own dev code for the plugin, as with @CAG2 pt2 answer. (Personally, I had trouble finding a 'product.json' file; perhaps you need an insider's build of VS code for that kind of thing [edit]: https://code.visualstudio.com/api/advanced-topics/using-proposed-api, in which case I think you'd be editing 'package.json').
Please update the python extension to the latest version
or install the pre-release version directly. ( may be more useful to you )
this will basically solve your problem.
If the error continues, follow these steps:
- Uninstall Python extension (if you have pylance uninstall it first). Uninstall any other extension that is failing.
- Close all instances of VS Code.
- Go to, %USERPROFILE%/.vscode/extensions (on windows) or ~/.vscode/extensions on Linux/Mac.
- Delete any folder with the name starting with ms-python.python*
- Start VS Code, and install Python extension (also pylance if you uninstalled it in step 1).
I was having this issue and tried the above answer and it still didn't work. It turns out I hadn't installed python on my system yet. I didn't realize because I normally use it remotely.
From the VSCode documentation:
Quick start
- Step 1. Install a supported version of Python on your system (note: that the system install of Python on macOS is not supported).
- Step 2. Install the Python extension for Visual Studio Code.
- Step 3. Open or create a Python file and start coding!
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.
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
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 !
Try disabling all other python extensions in VSCode. I had the same issue because a different Python VS extension was conflicting with the official extension. Here's a link that might be able to help you in more detail.
It's hard to give you a more specific answer for this type of question without knowing more about your setup.
EDIT: Look at the comment thread on this answer if you need more details
You should go through standard troubleshooting procedures like uninstalling and reinstalling ms-python.python. Check if you have multiple python extensions installed and that you only have one installed. This might give you a bit more detail.
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