[BUG] Cowork: "Failed to create bridge sockets after 5 attempts" on all sessions after update to Claude 1.3036.0 (SDK 2.1.111)

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?

Error: Failed to create bridge sockets after 5 attempts
Claude Code process exited with code 1

What Should Happen?

After Claude Desktop auto-updated to version 1.3036.0 (cf521c), Cowork fails on every session (new and resumed) with:
Error: Failed to create bridge sockets after 5 attempts
Claude Code process exited with code 1
Cowork was working normally before the update. The update is the only change.
Environment:

Claude Desktop: 1.3036.0 (cf521c), 2026-04-16T16:17:33.000Z
VM SDK: 2.1.111
macOS Apple Silicon (MacBook Pro)
socat: installed at /opt/homebrew/bin/socat
No VPN, firewall, MDM, or network filtering tools

Error Messages/Logs

Steps to Reproduce

Update Claude Desktop to 1.3036.0
Open Cowork, start new conversation
Send any message → immediate error

Troubleshooting attempted (none resolved it):

Full app quit + relaunch
Full Mac reboot
Cache wipe: rm -rf ~/Library/Caches/Claude and ~/Library/Application Support/Claude/claude-code-vm
Stale socket cleanup: rm -rf /tmp/claude-*
socat install via Homebrew

Log (~/Library/Logs/Claude/cowork_vm_node.log):
[VM:start] Startup complete, total time: 7768ms
[postConnect] Installing SDK: version=2.1.111
[Spawn:vm] OAuth token approved with MITM proxy
[Spawn:vm] Spawn succeeded in 101ms
[vm-stderr] Error: Failed to create bridge sockets after 5 attempts
[Process] Exited, code=1, signal=null, duration=1133ms, oom=false
VM starts cleanly, spawn confirms, then bridge sockets fail 1s later. 100% reproducible.
Related: #23746, #19503, #46029. Same bug class has recurred across multiple updates.

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

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_