extension activation failed typeerror s notebooks ondidchangecellmetadata is not a function

VS Code Jupyter extension fails to activate: "Typ"eError: this.vscNotebook.onDidChangeNotebookCellExecutionState is not a function

stackoverflow.com › questions › 79786069 › vs-code-jupyter-extension-fails-to-activate-typeerror-this-vscnotebook-ondid

I just had the same issue but downgrading only the Jupyter extension didn't help.

What worked for me were the following versions of Jupyter and Python extensions:

Extension	Version
Jupyter	2025.7.0
Jupyter Cell Tags	0.1.9
Jupyter Keymap	1.1.2
Jupyter Notebook Renderers	1.3.0
Jupyter Slide Show	0.1.6
Pylance	2025.7.1
Python	2025.7.1
Python Debugger	2025.10.0
Python Environments	1.2.0

I hope that list helps anyone encountering the problem in the future. It surely would have saved me quite some time.

Answer from jullrich on Stack Overflow

GitHub

github.com › microsoft › vscode-jupyter › issues › 11174

Extension activation failed [TypeError: s.notebooks.onDidChangeCellMetadata is not a function] · Issue #11174 · microsoft/vscode-jupyter

August 22, 2022 - Extension activation failed [TypeError: s.notebooks.onDidChangeCellMetadata is not a function]#11174

Author quaesitor-scientiam

GitHub

github.com › microsoft › azuredatastudio › issues › 21305

workbench.desktop.main.js : extension activation failed TypeError: s.notebooks.onDidChangeCellMetadata is not a function · Issue #21305 · microsoft/azuredatastudio

ERR [Extension Host] extension activation failed TypeError: s.notebooks.onDidChangeCellMetadata is not a function at d.addEventHandlers (c:\Users\admin.azuredatastudio\extensions\ms-toolsai.jupyter-2021.8.1046824664\out\client\extension.js:52:550940) at new d (c:\Users\admin.azuredatastudio\extensions\ms-toolsai.jupyter-2021.8.1046824664\out\client\extension.js:52:548994) at Object.t.resolveInstance (c:\Users\admin.azuredatastudio\extensions\ms-toolsai.jupyter-2021.8.1046824664\out\client\extension.js:52:263464) at c:\Users\admin.azuredatastudio\extensions\ms-toolsai.jupyter-2021.8.1046824664\

Discussions

Jupyter Extension activation failed.

Environment data VS Code version: 1.57.0-insider Jupyter Extension version: 2021.6.831144556 Python Extension version: 2021.6.829598502-dev OS (Windows | Mac | Linux distro) and version: Win10 Ente... More on github.com

github.com

May 11, 2021

Updating to 1.67.1 causes Jupyter to no longer be able to open.

Issue Type: Bug Jupyter can't start after updating to 1.67.1 and says to open the developer tools to investigate. Extension version: 2022.4.1011282140 VS Code version: Code 1.67.1 (da15b6fd3ef8... More on github.com

github.com

May 12, 2022

Extension Activation Failed

Type: Bug Jupyter notebooks will not find kernel (no selection option). Extension activation failed message upon opening / restarting VS code. Console logs below: """log.ts:460 ERR E... More on github.com

github.com

October 9, 2025

Extension activation failed on TypeError

Environment data VS Code version: 1.55.0-insider Jupyter Extension version (available under the Extensions sidebar): v2021.5.697286501 Python Extension version (available under the Extensions sideb... More on github.com

github.com

March 29, 2021

Stack Overflow

stackoverflow.com › questions › 79786069 › vs-code-jupyter-extension-fails-to-activate-typeerror-this-vscnotebook-ondid

VS Code Jupyter extension fails to activate: "Typ"eError: this.vscNotebook.onDidChangeNotebookCellExecutionState is not a function - Stack Overflow

Top answer

1 of 2

I just had the same issue but downgrading only the Jupyter extension didn't help.

What worked for me were the following versions of Jupyter and Python extensions:

Extension	Version
Jupyter	2025.7.0
Jupyter Cell Tags	0.1.9
Jupyter Keymap	1.1.2
Jupyter Notebook Renderers	1.3.0
Jupyter Slide Show	0.1.6
Pylance	2025.7.1
Python	2025.7.1
Python Debugger	2025.10.0
Python Environments	1.2.0

I hope that list helps anyone encountering the problem in the future. It surely would have saved me quite some time.

2 of 2

Updating both my vscode and jupyter version fixed it for me! seems to have been a temporary version incompatibility

GitHub

github.com › microsoft › vscode-jupyter › issues › 5829

Jupyter Extension activation failed. · Issue #5829 · microsoft/vscode-jupyter

May 11, 2021 - extension activation failed TypeError: s.notebook.onDidChangeNotebookCellExecutionState is not a function at new d (c:\Users\vyizh12\.vscode-insiders\extensions\ms-toolsai.jupyter-2021.6.831144556\out\client\extension.js:90:450992) at Object.t.resolveInstance (c:\Users\vyizh12\.vscode-insiders\extensions\ms-toolsai.jupyter-2021.6.831144556\out\client\extension.js:52:263270) at c:\Users\vyizh12\.vscode-insiders\extensions\ms-toolsai.jupyter-2021.6.831144556\out\client\extension.js:52:262475 at Array.map (<anonymous>) at Object.t.resolveInstance (c:\Users\vyizh12\.vscode-insiders\extensions\ms-t

Published May 11, 2021

Author linette-zyy

GitHub

github.com › microsoft › vscode-jupyter › issues › 10000

Updating to 1.67.1 causes Jupyter to no longer be able to open. · Issue #10000 · microsoft/vscode-jupyter

May 12, 2022 - Please use the Buffer.alloc(), Buffer.allocUnsafe(), or Buffer.from() methods instead.(UseElectron --trace-deprecation ... to show where the warning was created) E @ console.ts:137 notificationsAlerts.ts:42 Extension activation failed, run the 'Developer: Toggle Developer Tools' command for more information. onDidChangeNotification @ notificationsAlerts.ts:42 log.ts:313 ERR [Extension Host] extension activation failed TypeError: s.notebooks.onDidChangeCellMetadata is not a function at u.addEventHandlers (/Users/daniel/.vscode/extensions/ms-toolsai.jupyter-2022.3.1000901801/out/extension.js:2:7

Published May 12, 2022

Author Lolologist

GitHub

github.com › microsoft › vscode-jupyter › issues › 9590

Jupyter won't activate with new Insiders · Issue #9590 · microsoft/vscode-jupyter

Python Extension version (available ... notebook APIs that have been removed by VS Code. onDidChangeCellMetadata has been removed in favor of onDidChangeNotebookDocument....

GitHub

github.com › microsoft › vscode-jupyter › issues › 17036

Extension Activation Failed · Issue #17036 · microsoft/vscode-jupyter

October 9, 2025 - Console logs below: """log.ts:460 ERR Extension 'ms-toolsai.jupyter' wants API proposal 'notebookCellExecutionState' but that proposal DOES NOT EXIST. Likely, the proposal has been finalized (check 'vscode.d.ts') or was abandoned. error @ log.ts:460 log.ts:460 ERR [Extension Host] extension activation failed TypeError: this.vscNotebook.onDidChangeNotebookCellExecutionState is not a function at new Rk..."""

Author mbosseme

GitHub

github.com › microsoft › vscode-jupyter › issues › 9602

VSC Insider 1.67 and Jupyter NB extension incompatible · Issue #9602 · microsoft/vscode-jupyter

User belongs to experiment group 'jupyterTest' User belongs to experiment group 'jupyterEnhancedDataViewer' Error 05:31:01: extension activation failed [TypeError: s.notebooks.onDidChangeCellMetadata is not a function at u.addEventHandlers (/home/ekhomin/.vscode-server-insiders/extensions/ms-toolsai.jupyter-2022.3.1000901801/out/extension.js:2:735175) at new u (/home/ekhomin/.vscode-server-insiders/extensions/ms-toolsai.jupyter-2022.3.1000901801/out/extension.js:2:733840) at Object.t.resolveInstance (/home/ekhomin/.vscode-server-insiders/extensions/ms-toolsai.jupyter-2022.3.1000901801/out/exte

Find elsewhere

Google Bing Mojeek

GitHub

github.com › microsoft › vscode-jupyter › issues › 5344

Extension activation failed on TypeError · Issue #5344 · microsoft/vscode-jupyter

March 29, 2021 - extension activation failed TypeError: s.notebook.onDidChangeCellExecutionState is not a function at new d (c:\Users\allytice\.vscode-insiders\extensions\ms-toolsai.jupyter-2021.5.697286501\out\client\extension.js:49:766571) at Object.resolveInstance (c:\Users\allytice\.vscode-insiders\extensions\ms-toolsai.jupyter-2021.5.697286501\out\client\extension.js:47:239920) at c:\Users\allytice\.vscode-insiders\extensions\ms-toolsai.jupyter-2021.5.697286501\out\client\extension.js:47:239125 at Array.map (<anonymous>) at Object.resolveInstance (c:\Users\allytice\.vscode-insiders\extensions\ms-toolsai.j

Author alyssajotice

GitHub

github.com › Microsoft › vscode-jupyter › issues › 17030

Activation of the Jupyter extension failed in VS Code 1.104.3 · Issue #17030 · microsoft/vscode-jupyter

October 8, 2025 - Type: Bug Here is the error in the output of vscode. Failed to active the Jupyter Extension [TypeError: this.vscNotebook.onDidChangeNotebookCellExecutionState is not a function at new Rk (.vscode\extensions\ms-toolsai.jupyter-2023.8.1002...

Author prcheruk

GitHub

github.com › microsoft › vscode-jupyter › issues › 17100

Run Error Jupyter NoteBook · Issue #17100 · microsoft/vscode-jupyter

October 20, 2025 - extension activation failed TypeError: this.vscNotebook.onDidChangeNotebookCellExecutionState is not a function at new Rk (c:\Users\Aboch\.vscode\extensions\ms-toolsai.jupyter-2023.8.1002501831\out\extension.node.js:24:501992) at f (c:\Users\Aboch\.vscode\extensions\ms-toolsai.jupyter-2023.8.1002501831\out\extension.node.js:2:544315) at c:\Users\Aboch\.vscode\extensions\ms-toolsai.jupyter-2023.8.1002501831\out\extension.node.js:2:546205 at t.resolveInstance (c:\Users\Aboch\.vscode\extensions\ms-toolsai.jupyter-2023.8.1002501831\out\extension.node.js:2:546232) at c:\Users\Aboch\.vscode\extensio

Author Ilya-creat

Iifx

iifx.dev › en › articles › 460270125 › fixing-the-typeerror-is-not-a-function-in-vs-code-jupyter-activation

visual studio code - Fixing the 'TypeError: is not a function' in VS Code Jupyter Activation - jupyter notebook - vscode extensions

The error message you're seeing, "TypeError: this.vscNotebook.onDidChangeNotebookCellExecutionState is not a function", strongly suggests an incompatibility between your VS Code version and the Jupyter extension version.

Lightrun

lightrun.com › answers › microsoft-vscode-jupyter-jupyter-wont-activate-with-new-insiders

Jupyter won't activate with new Insiders

April 5, 2022 - Python Extension version (available ... notebook APIs that have been removed by VS Code. onDidChangeCellMetadata has been removed in favor of onDidChangeNotebookDocument....

GitHub

github.com › microsoft › vscode-jupyter › issues › 5114

Jupyter extension is not activating on codespaces · Issue #5114 · microsoft/vscode-jupyter

User belongs to experiment group 'pythonJediLSP' User belongs to experiment group 'jupyterTestcf' User belongs to experiment group 'pythonDiscoveryModule' User belongs to experiment group 'NativeNotebookEditor' Error 2021-03-11 02:02:10: extension activation failed TypeError: s.notebook.onDidChangeCellLanguage is not a function at u.addEventHandlers (/root/.vscode-remote/extensions/ms-toolsai.jupyter-2021.4.625511240/out/client/extension.js:47:539381) at new u (/root/.vscode-remote/extensions/ms-toolsai.jupyter-2021.4.625511240/out/client/extension.js:47:537652) at Object.t.resolveInstance (/r

GitHub

github.com › microsoft › vscode › issues › 125381

[Extension Host] extension activation failed TypeError · Issue #125381 · microsoft/vscode

June 3, 2021 - Extension activation failed, run the 'Developer: Toggle Developer Tools' command for more information. onDidChangeNotification @ workbench.desktop.main.js:741 (anonymous) @ workbench.desktop.main.js:741 fire @ workbench.desktop.main.js:60 ...

Author mage1k99

reddit.com › r/archlinux › can't use jupyter notebooks in vscode

r/archlinux on Reddit: Can't use jupyter notebooks in vscode

November 21, 2021 -

Hi there,

I use Jupyter notebooks in vscode (with the code package). I used to deal with the official Microsoft package which seemed outdated (alert of a new version available always popping) so I decided to try the unofficial one.

Here is my problem: even with the extension installed, I can't use any ipynb file. I can see the cells, but not execute them...

Here is the error: "Extension activation failed, run the 'Developer: Toggle Developer Tools' command for more information."

Thank you very much.

ABOUT:

Version: 1.62.0

Commit: b3318bc0524af3d74034b8bb8a64df0ccf35549a

Date: 2021-11-07T19:37:13.664Z

Electron: 13.6.2

ERROR:

electron/js2c/renderer_init.js:113 Electron Security Warning (Insecure Content-Security-Policy This renderer process has either no Content Security)
Policy set or a policy with "unsafe-eval" enabled. This exposes users of
this app to unnecessary security risks.
For more information and help, consult
https://electronjs.org/docs/tutorial/security.
This warning will not show up
once the app is packaged.
(anonymous @ electron/js2c/renderer_init.js:113)
log.ts:289 INFO Starting extension host with pid 6798.
log.ts:289 INFO [LocalProcessExtensionHost]: IExtensionHostStarter.start( took 51 ms.)
abstractExtensionService.ts:1151 Extension 'ms-python.python cannot use PROPOSED API (must started out of dev or enabled via --enable-proposed-api)
updateEnableProposedApi @ abstractExtensionService.ts:1151
abstractExtensionService.ts:1151 Extension 'ms-toolsai.jupyter cannot use PROPOSED API (must started out of dev or enabled via --enable-proposed-api)
updateEnableProposedApi @ abstractExtensionService.ts:1151
abstractExtensionService.ts:918 [ms-toolsai.jupyter]: interactive/toolbar is a proposed menu identifier and is only available when running out of dev or with the following command line switch: --enable-proposed-api ms-toolsai.jupyter
_logMessageInConsole @ abstractExtensionService.ts:918
abstractExtensionService.ts:918 [ms-toolsai.jupyter]: interactive/cell/title is a proposed menu identifier and is only available when running out of dev or with the following command line switch: --enable-proposed-api ms-toolsai.jupyter
_logMessageInConsole @ abstractExtensionService.ts:918
log.ts:301 ERR [Extension Host] (node:6798 [DEP0005] DeprecationWarning: Buffer( is deprecated due to security and usability issues. Please use the Buffer.alloc(, Buffer.allocUnsafe(), or Buffer.from() methods instead.)))
(Use \electron --trace-deprecation ...` to show where the warning was created)`
console.ts:137 [Extension Host] (node:6798 [DEP0005] DeprecationWarning: Buffer( is deprecated due to security and usability issues. Please use the Buffer.alloc(, Buffer.allocUnsafe(), or Buffer.from() methods instead.(Use \electron --trace-deprecation ...` to show where the warning was created))))`
E @ console.ts:137
loader.js:1 Failed to load resource: the server responded with a status of 404 ()
2console.ts:137 [Extension Host] No editors associated with document: /home/elyur/Python/s5/Projet1/samplingasine_2021.ipynb
E @ console.ts:137
notificationsAlerts.ts:42 Extension activation failed, run the 'Developer: Toggle Developer Tools' command for more information.
onDidChangeNotification @ notificationsAlerts.ts:42
log.ts:301 ERR [Extension Host] extension activation failed Error: [ms-toolsai.jupyter]: Proposed API is only available when running out of dev or with the following command line switch: --enable-proposed-api ms-toolsai.jupyter
at S (/usr/lib/code/out/vs/workbench/services/extensions/node/extensionHostProcess.js:94:81081)
at w (/usr/lib/code/out/vs/workbench/services/extensions/node/extensionHostProcess.js:94:81028)
at Object.onDidChangeCellMetadata (/usr/lib/code/out/vs/workbench/services/extensions/node/extensionHostProcess.js:103:41477)
at u.addEventHandlers (/home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:570428)
at new u (/home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:569096)
at Object.t.resolveInstance (/home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:269067)
at /home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:268272
at Array.map (<anonymous>)
at Object.t.resolveInstance (/home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:268837)
at /home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:268272
at /home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:267220
at Array.map (<anonymous>)
at /home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:267192
at Array.map (<anonymous>)
at Object.t.resolveInstance (/home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:268837)
at /home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:268272
at Object.t.resolve (/home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:268535)
at /home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:259632
at e._get (/home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:259398)
at e.get (/home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:258110)
at a.get (/home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:90:383850)
at /home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:246955
at processTicksAndRejections (internal/process/task_queues.js:93:5)
at async /home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:37:734295
at async t.activate (/home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:37:733982)
at async Promise.all (index 0)
console.ts:137 [Extension Host] extension activation failed Error: [ms-toolsai.jupyter]: Proposed API is only available when running out of dev or with the following command line switch: --enable-proposed-api ms-toolsai.jupyter
at S (/usr/lib/code/out/vs/workbench/services/extensions/node/extensionHostProcess.js:94:81081)
at w (/usr/lib/code/out/vs/workbench/services/extensions/node/extensionHostProcess.js:94:81028)
at Object.onDidChangeCellMetadata (/usr/lib/code/out/vs/workbench/services/extensions/node/extensionHostProcess.js:103:41477)
at u.addEventHandlers (/home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:570428)
at new u (/home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:569096)
at Object.t.resolveInstance (/home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:269067)
at /home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:268272
at Array.map (<anonymous>)
at Object.t.resolveInstance (/home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:268837)
at /home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:268272
at /home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:267220
at Array.map (<anonymous>)
at /home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:267192
at Array.map (<anonymous>)
at Object.t.resolveInstance (/home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:268837)
at /home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:268272
at Object.t.resolve (/home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:268535)
at /home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:259632
at e._get (/home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:259398)
at e.get (/home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:258110)
at a.get (/home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:90:383850)
at /home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:52:246955
at processTicksAndRejections (internal/process/task_queues.js:93:5)
at async /home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:37:734295
at async t.activate (/home/elyur/.vscode-oss/extensions/ms-toolsai.jupyter-2021.10.100/out/client/extension.js:37:733982)
at async Promise.all (index 0)
E @ console.ts:137
10console.ts:137 [Extension Host] No editors associated with document: /home/elyur/Python/s5/Projet1/samplingasine_2021.ipynb