Cursor Extensions Not Working or Not Found

How to fix it

Try these in order — the most common fix is first.

1. 1. Install from VSIX

   Copy steps
   1. In VS Code open the extension page, gear icon > Download Extension
   2. In Cursor run Extensions: Install from VSIX from the Command Palette
   Did this fix it? Yes No

2. 2. Use Cursor's in-house extensions

   1. Search the Cursor Marketplace for the Cursor Python, C++, C# extensions and install them
   Did this fix it? Yes No

3. 3. Use open-source alternatives

   1. For C++ language features try clangd; for debugging try an Open VSX debugger
   Did this fix it? Yes No

4. 4. Ask the author to publish on open-vsx.org

   1. Open an issue on the extension repo
   Did this fix it? Yes No

Symptoms

Extension is missing from search, install fails, or Microsoft C/C++, C# or Pylance won't activate.

Why it happens

• Cursor uses an Open VSX-compatible marketplace since mid-2025
• Extension author never published to Open VSX
• Microsoft extensions check for the host editor and refuse forks
• Devcontainer extensions not on Open VSX do not auto-install

This guide also covers

• cursor extensions not working
• cursor extension not found
• cursor pylance
• cursor c++ extension

Other Cursor errors

• Cursor Usage Limit Reached
• Cursor Rate Limit Exceeded
• Cursor Agent Not Working
• Cursor High Load Error (ERROR_RESOURCE_EXHAUSTED)
• Cursor Keeps Reconnecting or Connection Failed
• Cursor Slow, High CPU or Memory Usage
• Cursor MCP Not Working: Server Connected but No Tools
• Can't Use Cursor Auto After Included Usage Is Gone