[BUG] Cowork Tab Not Appearing on Claude Desktop for Windows — yukonSilver Unsupported

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?

The Cowork tab does not appear in Claude Desktop for Windows. CoworkVMService is confirmed running via PowerShell. The subscription is Pro plan, active and valid until April 2027. The log file at %APPDATA%\Claude\logs\cowork_vm_node.log shows that the internal VM compatibility profile "yukonSilver" is returning status=unsupported on every application launch since 18 April 2026, causing the Cowork tab to be suppressed entirely.

What Should Happen?

The Cowork tab should appear in Claude Desktop alongside the Chat tab for a user on a valid Pro plan with CoworkVMService running and a supported Windows installation.

Error Messages/Logs

2026-04-26 12:49:27 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...
2026-04-26 12:49:28 [info] [VM] Loading vmClient (TypeScript) module...
2026-04-26 12:49:28 [info] [VM] Module loaded successfully

Steps to Reproduce

1. Install Claude Desktop for Windows from claude.com/download using the current MSIX installer.
2. Launch Claude Desktop signed in to a valid Pro plan account.
3. Observe that only the Chat tab is visible. No Cowork tab is present.
4. Run Get-Service CoworkVMService in Administrator PowerShell — status returns Running.
5. Run Get-Content "$env:APPDATA\Claude\logs\cowork_vm_node.log" -Tail 50 — output shows repeated yukonSilver not supported (status=unsupported) entries on every launch.

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Not installed

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_