[BUG] Report: Claude Code VS Code Extension crashes with exit code 3221225477 on Windows 11 x64

[KalkiConsulting23]

Preflight Checklist

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

What's Wrong?

The Claude Code VS Code extension crashes immediately on launch with exit code 3221225477 (0xC0000005 = STATUS_ACCESS_VIOLATION). The login screen appears briefly but exits before authentication can complete, causing the browser OAuth callback to fail with ERR_CONNECTION_REFUSED on localhost.

What Should Happen?

Expected Behavior:
Extension should launch successfully and complete OAuth authentication via browser.

Actual Behavior:
Extension crashes with STATUS_ACCESS_VIOLATION before the OAuth callback server is ready to receive the login response.

Error Messages/Logs

exit code 3221225477

Steps to Reproduce

1. Install Claude Code VS Code extension on Windows 11 x64
2. Click the Claude Code icon in the sidebar
3. Extension attempts to open browser for OAuth login
4. Browser redirects to localhost callback URL
5. Connection is refused — localhost callback fails
6. Extension panel shows: `Claude Code process exited with code 3221225477

Claude Model

Not sure / Multiple models

Is this a regression?

No, this never worked

Last Working Version

No response

Claude Code Version

v2.1.169

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

• Running claude directly in PowerShell terminal works correctly
• The crash occurs specifically when launching via the VS Code extension GUI
• Git Bash (MINGW64) causes a segmentation fault; PowerShell does not
• Antivirus exclusions were added for npm and VS Code folders — did not resolve the issue
• Setting terminal.integrated.defaultProfile.windows to PowerShell did not resolve the extension crash
• Authentication via claude config set -g apiKey in terminal is the only working workaround