[BUG] Failed to start Claude's workspace — Request error: net::ERR_CONNECTION_CLOSED

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?

Confirming this issue — macOS Tahoe 26.4.1 + Apple M1

Adding my report as another affected user to help prioritize this fix.

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Environment

| Field | Detail |
|---|---|
| macOS Version | Tahoe 26.4.1 |
| Hardware | Apple M1 (Apple Silicon) |
| Available Disk Space | ~173 GB free |
| Claude Desktop Version | Latest (downloaded from claude.com/download) |
| Subscription | Max plan |

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Symptom

Every time I open Cowork, the workspace fails to start with:

"Failed to start Claude's workspace — Request error: net::ERR_CONNECTION_CLOSED"

The error is persistent and reproducible 100% of the time.

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Troubleshooting Already Attempted (all failed)

• Restarted Claude Desktop multiple times
• Restarted the Mac
• Used the in-app "Reinstall the workspace" option — same error returns immediately after reinstall

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Notes

• Regular Chat mode works perfectly — only Cowork is affected
• The issue started after upgrading to macOS Tahoe 26.x; Cowork was working normally on the previous macOS version
• Based on the logs and prior reports in this thread, this appears to be the same bridge socket / Virtualization.framework regression on macOS 26

Hoping to see a fix soon. Happy to provide Console logs or debug output if that would help.

What Should Happen?

Cowork should launch successfully and the workspace VM should start normally, exactly as it did before upgrading to macOS Tahoe 26.x. The user should be able to submit tasks and have Claude execute them in the isolated VM environment without any connection errors.

Error Messages/Logs

Error displayed in the Cowork UI:

> "Failed to start Claude's workspace
> Request error: net::ERR_CONNECTION_CLOSED
> Restarting Claude or your computer sometimes resolves this. If it persists, you can reinstall the workspace."

Based on patterns reported in this thread, the underlying log likely contains:


[VM:steps] guest_vsock_connect started
[VM:start] Connection timeout, last completed step: vm_boot
[VM:start] Startup failed: Error: VM connection timeout
[vm-stderr] Error: Failed to create bridge sockets after 5 attempts
[Process] Exited, code=1, signal=null, duration=~800ms, oom=false


*(Full Console logs available on request via ~/Library/Logs/Claude/)*

Steps to Reproduce

1. Use a Mac with Apple M1 chip running macOS Tahoe 26.4.1
2. Install the latest Claude Desktop from claude.com/download
3. Sign in with a Max plan account
4. Click on the Cowork tab in Claude Desktop
5. Observe the error banner: "Failed to start Claude's workspace — Request error: net::ERR_CONNECTION_CLOSED"
6. Try clicking "Reinstall the workspace" in the error prompt
7. Observe the same error reappears immediately after reinstall completes

Reproduces: 100% of the time

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Claude Code v2.1.119

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_