[BUG] 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?

Cowork fails to start with "VM service not running" error.
Every launch, yukonSilver VM engine marks system as unsupported
and deletes the bundle:

[cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported)
[deleteVMBundle] Deleting reinstall files...

VM never starts. Error persists after reinstall, bundle delete, and fresh install.

cowork_vm_node.log
cowork-service.log

What Should Happen?

Cowork should start successfully and VM should run.

Error Messages/Logs

[cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...
[deleteVMBundle] Deleting reinstall files from ...vm_bundles\claudevm.bundle
[deleteVMBundle] Reinstall files deleted (sessiondata.img and rootfs.img.zst preserved)
Service error: signature verification initialization failed: failed to get service executable path: The system cannot find the path specified.

Steps to Reproduce

1. Install Claude Desktop v1.1.7714 on Windows 11 Pro (25H2, Build 26200.8037)
2. Open Claude Desktop
3. Click on Cowork tab
4. Error appears: "Failed to start Claude's workspace — VM service not running"
5. Check cowork_vm_node.log — yukonSilver marked as unsupported, bundle deleted every launch
6. Issue persists after: full reinstall, Delete VM Bundle, fresh EXE install

Claude Model

None

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

Claude Desktop version: 1.1.7714

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_