[BUG] Claude Cowork: Claude Code process exited with code 126 on macOS Tahoe 26.4 — version 1.1617.0

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?

Cowork is completely non-functional. Every session attempt immediately fails with "Claude Code process exited with code 126.
Environment:

• Claude Desktop version: 1.1617.0 (8d6345) — 2026-04-09
• OS: macOS Tahoe 26.4
• Chip: Apple Silicon M5
• Subscription: Max Plan

What Should Happen?

Cowork workspace VM should initialize successfully and allow me to start a session and run tasks.

Error Messages/Logs

Claude Code process exited with code 126

Steps to Reproduce

1. Open Claude Desktop
2. Navigate to Cowork
3. Attempt to start a session
4. Observe: "Claude Code process exited with code 126" immediately

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude Desktop version: 1.1617.0 (8d6345) — 2026-04-09

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_