Claude Code crashes (0xc0000409, offset 0x36a8069) when spawned by Claude Desktop — works in interactive terminal

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?

Claude Code crashes immediately when spawned by Claude Desktop (both Cowork tab and Code tab). The error banner says "Claude Code crashed." The process exits with code 3221226505 (0xC0000409 STATUS_STACK_BUFFER_OVERRUN) about 9 seconds after being spawned, before producing any response.

What Should Happen?

Claude Code should start successfully and respond to tasks in both the Cowork and Code tabs.

Error Messages/Logs

Windows Event Log (Event ID 1000):
Faulting application: claude.exe
Exception code: 0xc0000409
Fault offset: 0x36a8069 (identical across all crashes, both 2.1.197 and 2.1.202)
had_first_response: false
seconds_to_outcome: 9
error_category: process_crashed
Report ID: 42245892-28bf-44ab-b9e5-1b06a6853892

Steps to Reproduce

1. Open Claude Desktop on Windows
2. Go to Cowork tab or Code tab
3. Send any message
4. Claude Code crashes every time before responding

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.202 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

• Interactive terminal works perfectly — same binary responds and creates files successfully
• Crash affects BOTH Cowork tab and Code tab (any headless spawn from Desktop app)
• Claude Desktop version: 1.18286.0.0 (MSIX package)
• Git for Windows 2.55 installed, CLAUDE_CODE_GIT_BASH_PATH set
• Windows Defender clean, no proxy, direct internet access
• Bug persists across Claude Code 2.1.197 and 2.1.202 with identical fault offset