# Cursor won't load

**URL:** <https://forum.cursor.com/t/cursor-wont-load/158137>\
**Category:** Bug Reports\
**Tags:** performance, crashes, windows\
**Created:** [April 16, 2026, 6:12am UTC](https://forum.cursor.com/t/cursor-wont-load/158137 "2026-04-16T06:12:02Z")\
**Posts on this page:** 1\
**Showing post:** 5

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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:** [April 16, 2026, 7:09am UTC](https://forum.cursor.com/t/cursor-wont-load/158137/5 "2026-04-16T07:09:33Z")

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Hey, thanks for the report. This is a known issue. The extension host is not starting properly on some Windows machines after recent updates, which breaks notebooks, terminal, and AI at the same time.

A few things to try:

1. Clear extension cache. Close Cursor, delete these folders, then restart:

```auto
%APPDATA%\Cursor\CachedExtensions
%APPDATA%\Cursor\CachedExtensionVSIXs

```

1. Full profile reset. Close Cursor, rename `%APPDATA%\Cursor` to `Cursor_backup`, then launch Cursor. This creates a fresh profile. If it works, reimport your extensions from VS Code.

2. Disable Python Environment extension. Some users found it conflicts with the Jupyter kernel and causes the hang. Worth trying if you use it.

3. If nothing helps, you can roll back to an earlier version to unblock your work for now.

Also, if you can grab the red errors from Help \> Toggle Developer Tools \> Console right after startup, that would help us narrow down why the extension host fails on your setup.

There is an active thread with the same issue here: [[Bug] Jupyter Notebooks & AI Panel broken after upgrading to Cursor 3](https://forum.cursor.com/t/bug-jupyter-notebooks-ai-panel-broken-after-upgrading-to-cursor-3/157278)

The team is aware of this. Your report helps with prioritization. Let me know how it goes.

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