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.
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:
Clear extension cache. Close Cursor, delete these folders, then restart:
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.
Disable Python Environment extension. Some users found it conflicts with the Jupyter kernel and causes the hang. Worth trying if you use it.
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.
