claude-code - 💡(How to fix) Fix [BUG] Cowork shows "yukonSilver not supported (status=unsupported)" on Windows 11 Pro with 11th Gen Intel i5-1155G7 — VM never initializes

Preflight Checklist

• I have searched existing issues and this hasn't been reported yet
• This is a single bug report (please file separate reports for different bugs)
• I am using the latest version of Claude Code

What's Wrong?

System information

• OS: Windows 11 Pro
• CPU: 11th Gen Intel Core i5-1155G7 @ 2.50GHz
• Claude Desktop: latest version (fresh install as of 2026-05-31)
• Subscription: Pro

What's wrong Cowork tab shows a virtualization error. The VM never initializes and the virtual network adapter (vEthernet cowork-vm-nat) is never created.

Diagnostics confirmed

• HyperVisorPresent: True
• Hardware virtualization active and confirmed via systeminfo
• Virtual Machine Platform: Enabled
• CoworkVMService: Running (Automatic)
• vm_bundles folder: never created (Claude discards the bundle immediately)
• Performed full clean uninstall and reinstall as administrator — issue persists

Log (cowork_vm_node.log) 2026-05-31 22:23:35 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle... 2026-05-31 22:23:53 [info] [VM] Loading vmClient (TypeScript) module... 2026-05-31 22:23:53 [info] [VM] Module loaded successfully

What Should Happen?

Expected behavior Cowork should recognize that hardware virtualization is fully enabled and initialize the VM workspace.

Related issues #29887, #32004, #27316

Error Messages/Logs

**Error message shown in Cowork tab**
"Plataforma de máquina virtual no disponible
El espacio de trabajo de Claude requiere Virtual Machine Platform en Windows. 
Habilita esta función y luego reinicia.
Feature enablement failed (exit code 1)"

(UI language is Spanish, translation: "Virtual Machine Platform not available. 
Claude's workspace requires Virtual Machine Platform on Windows. 
Enable this feature and then restart. Feature enablement failed (exit code 1)")

Steps to Reproduce

Steps to Reproduce

1. Install Claude Desktop for Windows (latest version) as administrator
2. Open Claude Desktop and navigate to the Cowork tab
3. Observe the virtualization error — VM never starts
4. Check cowork_vm_node.log — shows "yukonSilver not supported (status=unsupported)" repeatedly
5. Verify with Get-NetAdapter — vEthernet (cowork-vm-nat) is never created
6. Confirmed reproducible after full clean uninstall and reinstall

Claude Model

None

Is this a regression?

I don't know

Last Working Version

1.9659.2

Claude Code Version

1.9659.2.0

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

No response