[BUG] Cowork fails with "Claude Code process exited with code 1" after app update on macOS Tahoe 26.4.1 (M4 Pro)

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 fails immediately with the error "Claude Code process exited with code 1" on every task I try to run. Regular Claude chat works perfectly — only Cowork is affected.

The issue started today (April 16, 2026), immediately after installing the latest Claude Desktop app update. Cowork was working fine before the update.

Scope:

• ✅ Regular Claude chat: working fine
• ❌ Cowork: fails immediately with exit code 1 on every task

Environment:

• Machine: MacBook with Apple M4 Pro
• macOS version: Tahoe 26.4.1
• Claude Desktop version: Claude 1.3036.0 (cf521c) 2026-04-16T16:17:33.000Z

Steps already tried (none resolved the issue):

1. Restarted laptop
2. Signed out and signed back in
3. Started fresh tasks (not resuming old ones)
4. Full app reinstall (deleted app, downloaded fresh from claude.ai)
5. Deleted ~/Library/Application Support/Claude/ and related Cowork/sandbox folders
6. Cleared ~/Library/Caches/ entries for Claude/Anthropic
7. Still fails immediately with exit code 1 after every attempt

Additional note: Since regular chat works fine and the issue appeared right after the update, this looks like a regression in the Cowork sandbox/VM component in the latest release.

What Should Happen?

Cowork task should start and run normally, as it did before today's app update.

Error Messages/Logs

Steps to Reproduce

1. Open Claude Desktop (latest version) on macOS Tahoe 26.4.1, M4 Pro
2. Switch to Cowork
3. Start any new task
4. Observe: immediate error "Claude Code process exited with code 1"

<img width="374" height="159" alt="Image" src="https://github.com/user-attachments/assets/6419ec3c-11b6-445e-9f5a-ca1e296a58a4" />

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

not sure the version but just before latest version

Claude Code Version

Claude 1.3036.0 (cf521c) 2026-04-16T16:17:33.000Z

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_