[BUG] Claude's output is duplicated in the VS Code assistant window

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Yesterday, Claude Code crashed at one point, and since then, Claude's output has been duplicated in the VS Code window. I have tried exiting all VS Code windows, and even shutdown and restarted my PC (Windows 11), and the problem persists. I tried opening Claude up in a new VS Code window with a new project loaded, but I am still seeing the same duplication of output.

What Should Happen?

Claude should only output its response once.

Error Messages/Logs

Steps to Reproduce

1. Start VS Code
2. Ask Claude a question in the conversation window
3. Observe the response being echoed twice.

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.34

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_