[BUG]

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 extension crashes repeatedly with exit code 3221225477 (0xC0000005 - Windows Access Violation). The crash occurs both at startup and during active sessions. It has been happening for several weeks across multiple versions (2.1.145, 2.1.152, 2.1.168, 2.1.199). Sometimes Claude Code works for a few minutes before crashing mid-session.

What Should Happen?

Claude Code should run stably without crashing on Windows.

Error Messages/Logs

[error] Error spawning Claude (on channel ...): Error: Claude Code process exited with code 3221225477
[error] Failed to load config cache: Error: Claude Code process exited with code 3221225477
[error] claude auth status parse failed: SyntaxError: Unexpected end of JSON input
[error] Error from Claude (on channel ...): Error: Claude Code process exited with code 3221225477

Steps to Reproduce

1. Install Claude Code extension in VS Code on Windows
2. Open any project folder
3. Launch Claude Code panel
4. Either: (a) the process crashes immediately at startup, or (b) start a conversation and after a few minutes / ~80 messages the process crashes mid-session
5. Output logs show: "Claude Code process exited with code 3221225477"

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Unknown — issue has been occurring since at least version 2.1.145 and persists through 2.1.199

Claude Code Version

1. Install Claude Code extension in VS Code on Windows 2. Open any project folder 3. Launch Claude Code panel 4. Either: (a) the process crashes immediately at startup, or (b) start a conversation and after a few minutes / ~80 messages the process crashes mid-session 5. Output logs show: "Claude Code process exited with code 3221225477"

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

OS: Windows (64-bit)
VS Code extension version: 2.1.199
RAM: 16GB
Antivirus: McAfee uninstalled, Windows Defender active
Attempted fixes: McAfee exclusions, extension reinstall, deleting .claude.json, disabling Python environment auto-activation, disabling Use Python Environment setting. None resolved the issue permanently.