Cowork fails on Windows 11 Pro 25H2 — "Virtual Machine Platform not available" despite VMP being enabled (yukonSilver not supported)

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?

Environment

• Claude Desktop: 1.569.0 (49894a)
• OS: Windows 11 Pro, Version 25H2, Build 26200.7171
• Hardware: ASUS TUF Gaming A15 FA506NCG (AMD Ryzen, NVIDIA RTX 3050)

Description

Cowork cannot be launched. Claude Desktop shows:

"Plataforma de máquina virtual no disponible. El espacio de trabajo de Claude requiere Virtual Machine Platform en Windows. Habilita esta función y luego reinicia."

Steps to reproduce

1. Open Claude Desktop 1.569.0 on Windows 11 Pro 25H2
2. Click on Cowork
3. Error appears immediately

What I tried

• Enabled Virtual Machine Platform via DISM and PowerShell
• Verified VMP is Enabled via Get-WindowsOptionalFeature
• Verified AMD SVM is enabled in BIOS
• Clean reinstall of Claude Desktop
• Multiple reboots

Log output (cowork_vm_node.log)

2026-04-03 17:24:49 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...
2026-04-03 17:25:11 [info] [VM] Loading vmClient (TypeScript) module...
2026-04-03 17:25:11 [info] [VM] Module loaded successfully

Root cause (suspected)

The yukonSilver platform detection returns status=unsupported even though
VMP is correctly enabled. This appears to be a bug in Claude Desktop's platform
detection logic, not a user configuration issue.

Expected behavior

Cowork launches successfully on Windows 11 Pro 25H2 with VMP enabled.

Actual behavior

Error dialog blocks Cowork regardless. The "Habilitar" button does not resolve
the issue after reboot.

What Should Happen?

Cowork launches successfully. The Virtual Machine Platform is already
enabled on this system, so no error should appear.

Error Messages/Logs

Dialog: "El espacio de trabajo de Claude requiere Virtual Machine Platform 
en Windows. Habilita esta función y luego reinicia."

cowork_vm_node.log:
2026-04-03 17:24:49 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...
2026-04-03 17:25:11 [info] [VM] Loading vmClient (TypeScript) module...
2026-04-03 17:25:11 [info] [VM] Module loaded successfully

Steps to Reproduce

1. Open Claude Desktop 1.569.0 on Windows 11 Pro 25H2
2. Click on Cowork
3. Error dialog appears: "Virtual Machine Platform not available"
4. Click "Habilitar" button → reboot → same error persists

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

N/A — Claude Desktop 1.569.0 (49894a)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

Hardware: ASUS TUF Gaming A15 FA506NCG
Virtual Machine Platform: Enabled (verified via Get-WindowsOptionalFeature)
AMD SVM: Enabled in BIOS
Clean reinstall attempted. Multiple reboots. Issue persists.
The yukonSilver platform detection returns status=unsupported despite
VMP being correctly configured. This appears to be a detection bug in
Claude Desktop, not a user configuration issue.