[BUG] Cowork tab not showing on Windows 11 25H2 Build 26200 x64 — yukonSilver marked unsupported (still broken after #25136 closed)

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 tab is not showing on Windows — yukonSilver is marked as unsupported despite all virtualization features being enabled. This is a continuation of the bug originally reported in #25136, which was closed but not resolved for many users.

What Should Happen?

The Cowork tab should appear and yukonSilver should be recognized as supported on Windows 11 25H2 Build 26200 x64 with virtualization enabled.

Error Messages/Logs

2026-04-16 13:11:37 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...
2026-04-16 13:11:37 [info] [deleteVMBundle] Deleting reinstall files from C:\Users\X\AppData\Roaming\Claude\vm_bundles\claudevm.bundle
2026-04-16 13:11:37 [info] [deleteVMBundle] Reinstall files deleted (sessiondata.img and rootfs.img.zst preserved)

Steps to Reproduce

1. Install Claude Desktop v1.3036.0 on Windows 11 25H2 Build 26200 x64
2. Launch the app
3. Observe: only Chat and Code tabs visible, no Cowork tab
4. Check %APPDATA%\Claude\logs\cowork_vm_node.log — shows "yukonSilver not supported" on every launch

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

1.3036.0 (cf521c)

Platform

Other

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

This is the same bug as #25136 which was closed on Feb 13 but never actually fixed for Windows 11 Build 26200 users. The yukonSilver not supported error has been repeating in my logs since March 24, 2026 through every app update including the latest v1.3036.0. Many other users reported the same issue in #25136 after it was closed. OS Build confirmed via winver: Windows 11 25H2 Build 26200.