[BUG] Cowork: "Failed to create bridge sockets after 5 attempts" on Claude Desktop 1.3036.0 (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?

Preflight Checklist

I have searched existing issues and this hasn't been reported yet (issues #19503, #23746, #11079 describe the same error string but on older Claude Desktop versions with different root causes — Nix packaging, session resume, TMPDIR — none of which apply here)
This is a single bug report (please file separate reports for different bugs)
I am using the latest version of Claude Desktop

What's Wrong?
On Claude Desktop 1.3036.0 (today's build, 2026-04-16T16:17:33Z), every new Cowork session crashes immediately with:
Error: Failed to create bridge sockets after 5 attempts
The VM itself boots cleanly — networking comes up, API reachability check passes, all virtiofs mounts succeed, the claude subprocess spawns successfully inside the VM — and then the subprocess exits with code 1 after ~800-900ms with the bridge sockets error. This happens on every new session, regardless of the folder path, prompt, or whether a prior session existed.
Steps to Reproduce

Install Claude Desktop 1.3036.0 on macOS Tahoe 26.4.1 (Apple Silicon)
Open Cowork tab
Point at any folder (I used ~/Documents/Claude/Projects/test — simple path, no spaces)
Submit any prompt (e.g., "list files in this folder")
Observe session crash with "Claude Code process exited with code 1"

Expected Behavior
Cowork session starts, Claude responds to the prompt, tools execute normally.
Actual Behavior
VM boots, session spawns, claude subprocess inside the VM immediately exits with code 1. Bridge sockets are never created.
Log Excerpts
~/Library/Logs/Claude/cowork_vm_node.log
2026-04-16 12:58:18 [info] [VM:start] Startup complete, total time: 4769ms
2026-04-16 12:58:28 [info] [VM] API reachability: REACHABLE
2026-04-16 12:58:41 [info] [Spawn:create] id=d4d17d81-825e-4587-baee-30f9714d46de name=great-charming-tesla cmd=/usr/local/bin/claude args=--output-format stream-json --verbose --input-format stream-json --max-thinking-tokens 31999 --effort medium --model claude-opus-4-7 ...
2026-04-16 12:58:41 [info] [Spawn:vm] id=d4d17d81-825e-4587-baee-30f9714d46de OAuth token approved with MITM proxy
2026-04-16 12:58:41 [info] [Spawn:vm] id=d4d17d81-825e-4587-baee-30f9714d46de Spawn succeeded in 41ms
2026-04-16 12:58:42 [warn] [vm-stderr d4d17d81] Error: Failed to create bridge sockets after 5 attempts
2026-04-16 12:58:42 [info] [Process:d4d17d81-825e-4587-baee-30f9714d46de] Exited, code=1, signal=null, duration=841ms, oom=false
The pattern is identical on every session attempt — VM healthy, spawn succeeds, subprocess dies ~800ms later with bridge sockets error.
~/Library/Logs/Claude/coworkd.log
[KERNEL] 2026/04/16 19:49:56 [process:d96edf3a-...] mounted ... at /sessions/.../mnt/.claude/skills (mode=ro)
[KERNEL] 2026/04/16 19:49:56 [process:d96edf3a-...] wrote srt-settings (domains=23 parentProxy=false) to /etc/srt-settings/d96edf3a-....json
[KERNEL] 2026/04/16 19:49:56 [process:d96edf3a-...] started PID 2462
[KERNEL] 2026/04/16 19:49:57 [process:d96edf3a-...] direct child exited: code=1 signal=<nil>
VM kernel successfully starts the process, process exits 1 second later, all mounts cleanly unmounted.
Environment

Claude Desktop: 1.3036.0 (cf521c) 2026-04-16T16:17:33.000Z
macOS: 26.4.1 (Tahoe), build 25E253
Architecture: Apple Silicon
Plan: Max (if relevant)
Network: Home Wi-Fi, no VPN, no corporate proxy, no Tailscale
WPAD: Disabled (scutil --proxy shows no ProxyAutoConfigEnable or ProxyAutoDiscoveryEnable)

What I've Tried
All of the following attempted with no change in behavior:

Cleared stale state:

rm -rf /tmp/claude-*
rm -rf ~/Library/Application\ Support/Claude/vm_bundles
rm -rf ~/Library/Application\ Support/Claude/claude-code-vm
rm -rf ~/Library/Application\ Support/Claude/local-agent-mode-sessions

Fully quit Claude Desktop (Cmd+Q, confirmed no processes via ps aux | grep -i claude), relaunched, allowed full VM bundle re-download.
Disabled macOS WPAD auto-discovery (System Settings → Network → Proxies), confirmed via scutil --proxy that ProxyAutoConfig and ProxyAutoDiscovery are both off.
Installed socat on host via Homebrew (based on reading issues #19503 and #11079) — /opt/homebrew/bin/socat present, but this appears unrelated since the claude subprocess is executing inside the VM's Ubuntu 22.04 guest, not on the host.
Tested with a fresh simple folder path (~/Documents/Claude/Projects/test) — no difference.

Additional Notes

The error message "Failed to create bridge sockets after 5 attempts" matches the string in earlier issues (#19503, #23746, #11079), but each of those had a different root cause (allowedDomains=0 on resume, missing socat in PATH, missing TMPDIR in Nix packaging). None of those conditions apply here:

isResume=false in my logs (new sessions, not resumes)
allowedDomains=23 (not 0)
socat installed and on PATH
TMPDIR exists and is writable

The VM's API reachability check passes cleanly, so this isn't a networking issue at the VM↔internet layer. It's specifically the bridge sockets that the claude SDK creates inside the VM.
Happy to provide additional logs, run diagnostic commands, or test candidate fixes.

What Should Happen?

Claude should just work

Error Messages/Logs

Steps to Reproduce

open claude cowork and try to start any chat

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

1.3036.0 (today's build, 2026-04-16T16:17:33Z)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_