[BUG] Cowork Chrome MCP connection failure - persistent "not connected" error

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?

I'm experiencing a persistent connection issue between Cowork sessions and the Claude in Chrome extension that appears to be server-side.
Account details:
Email: [jmeier@meierfirm.com](mailto:jmeier@meierfirm.com)
Conversation ID: 215474338237403
OS: Windows 10
Chrome extension ID: fcoeoabgfenejglbffodgffbkcdhcgfn
Issue:
Cowork sessions cannot connect to my Chrome browser via the Claude in Chrome MCP. Every call to list_connected_browsers returns "Claude in Chrome is not connected."
What I've verified locally:
Chrome extension installed, enabled, and signed into [jmeier@meierfirm.com](mailto:jmeier@meierfirm.com)
Side panel works normally for in-browser tasks
Claude Desktop reinstalled; native messaging host manifest and registry key confirmed in place
Chrome fully restarted; full machine reboot performed
Connector toggled off/on in Settings
Waited 2-3 minutes between reconnection attempts
Cleared claude.ai cookies and tried incognito mode
Timeline:
Connection stopped working approximately 2-3 weeks ago, coinciding with the May 16th Cowork incident (resolved 18:24 UTC).
This appears to be a server-side relay issue between Cowork and the browser extension, as local configuration is correct.

What Should Happen?

The expected behavior is that when I ask claude cowork to work in chrome on a specific website that it will be able to take over the website and navigate it and conduct the activity I need. This should work just like the claude chrome extension does, which currently works just fine for me.

Error Messages/Logs

Steps to Reproduce

I tell claude cowork to open google.com using the chrome mcp and search for the best sushi restaurant in town but it says chrome is not connected. also the /chrome command does not show up either.

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

not sure but it worked about 2 weeks ago

Claude Code Version

Claude Desktop app : 1.7196.1 Claude Code (CCD) 2.1.142

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

_No response_