# Cursor 2.5.25 is broken (kernels not loading)

**URL:** <https://forum.cursor.com/t/cursor-2-5-25-is-broken-kernels-not-loading/152926>\
**Category:** Bug Reports\
**Tags:** data-science, extensions\
**Created:** [February 25, 2026, 2:21pm UTC](https://forum.cursor.com/t/cursor-2-5-25-is-broken-kernels-not-loading/152926 "2026-02-25T14:21:17Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Rakeh\_Saleem](https://avatars.discourse-cdn.com/v4/letter/r/76d3ee/32.png) [@Rakeh\_Saleem](https://forum.cursor.com/u/Rakeh_Saleem)\
**Post date:** [February 25, 2026, 2:21pm UTC](https://forum.cursor.com/t/cursor-2-5-25-is-broken-kernels-not-loading/152926/1 "2026-02-25T14:21:17Z")

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### Where does the bug appear (feature/product)?

Cursor IDE

### Describe the Bug

After a recent update to the cursor 2.5.25, I cannot select the kernel in Jupyter Notebook. It says “select kernel,” then keeps loading, and after so long, it shows nothing. It can not load previous chat history as well as now, and running .ipynb files have been an absolute mess.

To look into this, I tried to downgrade to the 2.3.35 version as well, which looks like a stable cursor version; it prompts the same error and can not load kernels. The project opens fine in Visual Studio, and I can run the Jupyter Notebook. No issue there whatsoever!

### Steps to Reproduce

Install 2.5.25 or 2.3.35 and see if its same issue? Not sure!

### Screenshots / Screen Recordings

 ![Debug.png](https://us1.discourse-cdn.com/cursor1/original/3X/a/2/a2f31c9f0ea3ea8d56b38caed60466695b9ad347.png)

### Operating System

Windows 10/11

### Version Information

Version: 2.3.35 (user setup) or 2.5.25  
VSCode Version: 1.105.1  
Commit: cf8353edc265f5e46b798bfb276861d0bf3bf120  
Date: 2026-01-13T07:39:18.564Z  
Electron: 37.7.0  
Chromium: 138.0.7204.251  
Node.js: 22.20.0  
V8: 13.8.258.32-electron.0  
OS: Windows\_NT x64 10.0.26200

### For AI issues: which model did you use?

Auto or sometimes Opus 4.6

### Does this stop you from using Cursor

Yes - Cursor is unusable

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**Author:** ![deanrie](https://sea3.discourse-cdn.com/cursor1/user_avatar/forum.cursor.com/deanrie/32/1263_2.png) [@deanrie](https://forum.cursor.com/u/deanrie)\
**Post date:** [February 25, 2026, 2:36pm UTC](https://forum.cursor.com/t/cursor-2-5-25-is-broken-kernels-not-loading/152926/3 "2026-02-25T14:36:04Z")

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Hey, thanks for the report.

Since the issue still happens on 2.3.35 after rolling back, it sounds like some user or extension data got corrupted during the update. A rollback doesn’t always fully reset everything.

A few things to try:

1. Reinstall the Jupyter extension: Uninstall it completely, restart Cursor, then install it again. This should reset cached kernel paths.
2. Clear the Jupyter extension storage: Delete this folder, then restart Cursor: `%APPDATA%\Cursor\User\globalStorage\ms-toolsai.jupyter`
3. Check for extension conflicts: Run `cursor --disable-extensions`, then install only the Jupyter extension and test.

Also, could you share:

- The Jupyter extension version you’re using (`Ctrl+Shift+X`, search for “Jupyter”)
- The output from the Jupyter output channel (`Ctrl+Shift+U` then pick “Jupyter” in the dropdown). Do you see any errors?

Since it works fine in VS Code, this is most likely related to the extension state in Cursor. Let me know what you find.

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**Author:** ![Rakeh\_Saleem](https://avatars.discourse-cdn.com/v4/letter/r/76d3ee/32.png) [@Rakeh\_Saleem](https://forum.cursor.com/u/Rakeh_Saleem)\
**Post date:** [February 25, 2026, 2:51pm UTC](https://forum.cursor.com/t/cursor-2-5-25-is-broken-kernels-not-loading/152926/4 "2026-02-25T14:51:59Z")

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Thank you, Dean, following steps 1 and 2 worked for 2.3.x version! I would disable the updates for now and will upgrade sometime in the future.

FYI: Jupyter’s Installation

Identifier `ms-toolsai.jupyter`

Version `2025.9.1`

Last Updated 2026-02-25, 09:46:16

Size 30.43MB

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**Author:** ![system](https://sea3.discourse-cdn.com/cursor1/user_avatar/forum.cursor.com/system/32/99069_2.png) [@system](https://forum.cursor.com/u/system)\
**Post date:** [March 19, 2026, 2:52pm UTC](https://forum.cursor.com/t/cursor-2-5-25-is-broken-kernels-not-loading/152926/6 "2026-03-19T14:52:53Z")

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