Cursor won't load

Support Bug Reports
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1

Where does the bug appear (feature/product)?

Cursor IDE

Describe the Bug

After launching Cursor, the application opens but becomes unresponsive in the following ways:

  • .ipynb (Jupyter notebook) tabs fail to load
  • Integrated terminal does not open
  • AI agents do not process requests

The issue occurs intermittently — not after every launch. Disabling extensions (–disable-extensions) does not resolve it. Clearing Cache and CachedData folders does not help either.

Steps to Reproduce

Intermittent — no consistent trigger identified yet.

Expected Behavior

Normal startup with all tabs, terminal, and agents functional.

Screenshots / Screen Recordings

cursor_bug.png
cursor_bug.png3287×1871 44.6 KB

Operating System

Windows 10/11

Version Information

Version: 3.1.15 (user setup)
VSCode Version: 1.105.1
Commit: 3a67af7b780e0bfc8d32aefa96b8ff1cb8817f80
Date: 2026-04-15T01:46:06.515Z
Layout: editor
Build Type: Stable
Release Track: Default
Electron: 39.8.1
Chromium: 142.0.7444.265
Node.js: 22.22.1
V8: 14.2.231.22-electron.0
OS: Windows_NT x64 10.0.19045

Does this stop you from using Cursor

Yes - Cursor is unusable

5

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:
%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

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

7

Thank you!

I clear extension chace along with restarting extension host and now it is working.

8

I run into the same issue with MacBook

9

Hey @Jian_Gong1. On Mac the paths are different, try this:

  1. Clear the extension cache. Quit Cursor, delete these folders, then restart:
~/Library/Application Support/Cursor/CachedExtensions
~/Library/Application Support/Cursor/CachedExtensionVSIXs

  1. Full profile reset. Quit Cursor, rename ~/Library/Application Support/Cursor to Cursor_backup, then launch it again. You’ll get a clean profile, and you can re-import extensions later from VS Code.

  2. If you’re using the Python Environment extension, try disabling it. It can conflict with the Jupyter kernel.

If that doesn’t help, send:

  • your Cursor version Cursor > About and your macOS version
  • your chip Intel or Apple Silicon
  • the red errors from Help > Toggle Developer Tools > Console right after launch

Mac symptoms can come from a different root bug than the Windows case in this thread, so the Console logs will really help us see what’s going on.

10

Yes, it worked, thanks!

11

Hey @deanrie , I had a similar issue on macOS and managed to get Cursor to load following your instructions and doing a full profile reset. Doing so caused me to lose all my previous chat history though (still in Cursor_backup). Is there any way to pull it over from the backups?

12

Hey @E-Rong_Yong, glad the reset helped and you can work again. Your chats should still be in the backup folder, you can copy them back.

Chat history is mainly stored in two places:

  • ~/Library/Application Support/Cursor_backup/User/globalStorage/state.vscdb - most of the chat data
  • ~/Library/Application Support/Cursor_backup/User/workspaceStorage/ - chat titles per project

Transcripts are also in ~/.cursor/projects/.

Steps, do this with Cursor fully closed, and check Activity Monitor to make sure there are no stuck processes:

  1. Close Cursor.
  2. Copy the files:
    cp "~/Library/Application Support/Cursor_backup/User/globalStorage/state.vscdb" \
   "~/Library/Application Support/Cursor/User/globalStorage/state.vscdb"

cp -R "~/Library/Application Support/Cursor_backup/User/workspaceStorage/" \
      "~/Library/Application Support/Cursor/User/workspaceStorage/"
  3. Open Cursor again.

I’d recommend copying only globalStorage and workspaceStorage, not the whole Cursor_backup/User folder, so you don’t bring back cached extension state that likely caused the original freeze.

Just in case, make a copy of the backup folder before you start. Let me know how it goes.

14

Hey @deanrie . The issue re-occured again, so I tried this same fix, but pulled over the foldersUser/globalStorage and User/workspaceStorage as you have mentioned. This caused the same loading issue, so I wiped the profile again and added folders one at a time until the bug was reproduced.

It appears one of the folders in User/workspaceStorage is the cause, I am still unable to recover my chats.

15

Hey, great diagnosis. Narrowing it down to a single folder in workspaceStorage/ really helps. Looks like there’s a corrupted state.vscdb in there, or some extension state got messed up, and the extension host hangs on it during startup.

To restore everything except the broken folder:

  1. Close Cursor.
  2. Delete the problematic subfolder from Cursor_backup/User/workspaceStorage/ or just don’t copy it.
  3. Copy the rest:
    cp -R "~/Library/Application Support/Cursor_backup/User/workspaceStorage/" \
      "~/Library/Application Support/Cursor/User/workspaceStorage/"
  4. Start Cursor.

About chats, there are two good news items:

  • Most data is in globalStorage/state.vscdb. If you’ve already restored it, your chats should show up in history. You’ll only lose the workspace link for that one broken folder, not the threads themselves.
  • Chat transcripts are also stored separately in ~/.cursor/projects/. That path isn’t touched by a profile reset, so even if something went really wrong with state.vscdb, check there. Your project chats should still be there.

Let me know how it goes.

16

It was usable 10 days ago, but not anymore. GTP and Claude work individually, but these two models in the cursor are unusable, displaying a loading message.