[BUG] Claude Cowork crashes with "exited with code 1" on first message — all sessions affected (new and existing), v1.3036.0 macOS

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?

Every Cowork session crashes immediately on the first message with:

Something went wrong Claude Code process exited with code 1 You can restart the conversation from an earlier message.

This affects both new Cowork sessions and existing sessions (confirmed by attempting to resume a session from 11 days ago — same crash). Regular (non-Cowork) Claude projects on claude.ai work normally.

This appears related to issue #46029 but differs in two key ways:

1. Newer build (1.3036.0 vs. 1.1617.0 reported there)
2. Existing sessions also crash (issue #46029 reported existing sessions resumed fine)

What Should Happen?

Expected Behavior
Cowork session should accept the message and respond normally.

Actual Behavior
Process exits with code 1 on first message. "Go back" and "Try again" buttons shown but retrying produces the same error.

Error Messages/Logs

Steps to Reproduce

Steps to Reproduce

1. Open Claude Desktop on macOS 15.7.4
2. Open any Cowork project (new or existing)
3. Send any message
4. Session crashes with exit code 1 immediately

Environment

• Claude Code version: 1.3036.0 (cf521c), built 2026-04-16T16:17:33.000Z
• OS: macOS Sequoia 15.7.4
• Surface: Cowork (Claude Desktop)
• Account type: Claude Pro

Troubleshooting already attempted

• Restarted the app
• Rebooted the machine
• Tried new sessions
• Tried resuming existing session from 11 days ago
• Confirmed regular (non-Cowork) Claude projects on claude.ai are unaffected

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

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

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_