[BUG] Cowork: yukonSilver marked as unsupported on Windows 11 Pro x64 with virtualization enabled

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 on Windows 11 Pro x64. The yukonSilver VM configuration is classified as "unsupported" despite virtualization being confirmed enabled in Task Manager. The VM never attempts to start. The connectors directory fails to load with the error "Could not load connectors directory."
The app has been reinstalled multiple times from claude.com/download. The issue has persisted since Feb 16, 2026 across every restart and reinstall. No admin access is available on this company-managed machine.

What Should Happen?

Cowork should detect the active hypervisor on Windows 11 Pro x64 and initialize the VM successfully. The connectors directory and workspace should load normally, as they do on the Chat tab.

Error Messages/Logs

yukonSilver classified as unsupported on every app launch:
2026-02-16 16:35:31 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...

VM skipped on every start attempt:
2026-02-16 16:36:12 [warn] [startVM] VM not supported (win32/x64), skipping
2026-02-16 16:36:12 [info] [Callbacks] Initializing VM event callbacks...
2026-02-16 16:36:12 [info] [VM] Loading vmClient (TypeScript) module...
2026-02-16 16:36:12 [info] [VM] Module loaded successfully
2026-02-16 16:36:12 [info] [Callbacks] VM event callbacks initialized

Swift VM module missing (appears from Feb 18 onward):
2026-02-18 09:15:47 [warn] [startVM] VM not supported (win32/x64), skipping
2026-02-18 09:15:47 [info] [Callbacks] Initializing VM event callbacks...
2026-02-18 09:15:47 [error] [Callbacks] Swift VM addon not available for callbacks

This pattern repeats hundreds of times from Feb 16 through Feb 24, 2026. No network status or API reachability entries ever appear because the process halts at platform detection. The %APPDATA%\Claude\vm_bundles\ directory does not exist because the app never downloads the VM bundle.

Steps to Reproduce

Steps to Reproduce

1. Install or update Claude Desktop from claude.com/download on Windows 11 Pro x64
2. Open Claude Desktop
3. Navigate to the Cowork tab
4. Observe "Could not load connectors directory" error
5. Check logs at %APPDATA%\Claude\logs\cowork_vm_node.log
6. Confirm repeated "VM not supported (win32/x64), skipping" entries

Claude Model

None

Is this a regression?

No, this never worked

Last Working Version

N/A

Claude Code Version

N/A (this is Cowork on Claude Desktop, not Claude Code CLI)

Platform

Other

Operating System

Windows

Terminal/Shell

Other

Additional Information

• Virtualization is confirmed enabled via Task Manager > Performance > CPU
• Company-managed machine with no local admin access
• Fresh download and reinstall from claude.com/download attempted multiple times
• Full quit and relaunch performed multiple times
• %APPDATA%\Claude\vm_bundles\ directory does not exist (VM bundle is never downloaded)
• Chat tab works normally; only Cowork is affected

Related issues with the same root cause:

#25136: Cowork tab not showing on Windows 11 Pro x64, yukonSilver unsupported
#27316: Virtualization not detected on Windows 11 Pro despite Hyper-V enabled
#27330: "VM not supported (win32/x64)" on Windows Pro with Hyper-V
#25155: VM boots but cannot reach Claude API on Windows Pro