[BUG] coworkd_upstream_failed connection_refused - persistent across 2 days on Mac

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?

Platform: macOS
Claude Desktop Version: 1.1062.0 (b81bcd) 2026-04-06
Plan: Pro

Issue:
Every Cowork task fails with the following error, consistently for 2 days:

API Error: 587 {"error":"coworkd_upstream_failed","category":"connection_refused","detail":"proxyconnect tcp: dial tcp 172.16.10.254:XXXX: connect: connection refused"}

The port number changes each time (9160, 9162, 9173, 9189, etc.) but the error is consistent.

Steps taken with no resolution:

• Fully quit and restarted Claude Desktop multiple times
• Logged out and logged back in
• No VPN in use
• Local IP is 192.168.1.x — no subnet conflict with 172.16.x.x range
• Cleared Cowork cache via Terminal
• Checked firewall — Claude Desktop not blocked
• Latest version confirmed

Tasks will run for a short period then consistently hit this error mid-task.
Regular Claude chat works fine. Only Cowork is affected.

This has been ongoing since April 7, 2026 and is completely blocking my workflow.

What Should Happen?

Tasks should be completed as prompted as per previous days of completed tasks

Error Messages/Logs

API Error: 587 {"error":"coworkd_upstream_failed","category":"connection_refused","detail":"proxyconnect tcp: dial tcp 172.16.10.254:9096: connect: connection refused"}
You can restart the conversation from an earlier message.

Steps to Reproduce

It is a task I have claude cowork doing

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Claude 1.1062.0 (b81bcd) 2026-04-06T21:20:28.000Z

Claude Code Version

Claude 1.1062.0 (b81bcd) 2026-04-06T21:20:28.000Z

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

Happening for 2 days now