›_ Claude Code Issues
Claude Code Issues / #49993

[BUG] related to known bugs #25136, #27316, #32004, #42227

Resolved 💬 2 comments Opened Apr 17, 2026 by franpeluffo-ship-it Closed May 25, 2026

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?

Preflight Checklist

  • [x] I have searched existing issues and this is related to known bugs #25136, #27316, #32004, #42227
  • [x] I am using the latest version of Claude Desktop

What's Wrong?

Cowork tab shows "Virtual Machine Platform not available" and prompts to enable the feature and restart. Restarting does not resolve the issue.

The log at %APPDATA%\Claude\logs\cowork_vm_node.log shows the following pattern repeating on every session, with the VM never progressing past this check:

2026-04-17 11:27:42 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...
2026-04-17 11:52:14 [info] [VM] Loading vmClient (TypeScript) module...
2026-04-17 11:52:14 [info] [VM] Module loaded successfully
2026-04-17 12:07:08 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...

Environment

  • Claude Desktop: v1.3109.0.0 (MSIX, installed from claude.com/download)
  • OS: Windows (details below)
  • CoworkVMService: Running
  • Virtual Machine Platform: Enabled
  • SignatureKind: Developer

Steps to Reproduce

  1. Install Claude Desktop v1.3109.0.0 (MSIX) from claude.com/download
  2. Enable Virtual Machine Platform in Windows Features
  3. Restart computer
  4. Open Claude Desktop and navigate to the Cowork tab
  5. Observe "Virtual Machine Platform not available" error

Expected Behavior
Cowork should detect that virtualization is enabled and successfully initialize the VM workspace.

Actual Behavior
Cowork repeatedly classifies the VM configuration as yukonSilver not supported (status=unsupported) and never downloads or initializes the VM bundle. The error persists after multiple restarts. sessiondata.vhdx is never created, confirming the VM never initializes.

Additional Notes
This appears to be the same misclassification bug reported in #25136, #27316, #32004, and #42227. CoworkVMService is confirmed running and all virtualization features are enabled. The issue is on Anthropic's side (incorrect hardware classification), not a user configuration problem.

What Should Happen?

Preflight Checklist

  • [x] I have searched existing issues and this is related to known bugs #25136, #27316, #32004, #42227
  • [x] I am using the latest version of Claude Desktop

What's Wrong?

Cowork tab shows "Virtual Machine Platform not available" and prompts to enable the feature and restart. Restarting does not resolve the issue.

The log at %APPDATA%\Claude\logs\cowork_vm_node.log shows the following pattern repeating on every session, with the VM never progressing past this check:

2026-04-17 11:27:42 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...
2026-04-17 11:52:14 [info] [VM] Loading vmClient (TypeScript) module...
2026-04-17 11:52:14 [info] [VM] Module loaded successfully
2026-04-17 12:07:08 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...

Environment

  • Claude Desktop: v1.3109.0.0 (MSIX, installed from claude.com/download)
  • OS: Windows (details below)
  • CoworkVMService: Running
  • Virtual Machine Platform: Enabled
  • SignatureKind: Developer

Steps to Reproduce

  1. Install Claude Desktop v1.3109.0.0 (MSIX) from claude.com/download
  2. Enable Virtual Machine Platform in Windows Features
  3. Restart computer
  4. Open Claude Desktop and navigate to the Cowork tab
  5. Observe "Virtual Machine Platform not available" error

Expected Behavior
Cowork should detect that virtualization is enabled and successfully initialize the VM workspace.

Actual Behavior
Cowork repeatedly classifies the VM configuration as yukonSilver not supported (status=unsupported) and never downloads or initializes the VM bundle. The error persists after multiple restarts. sessiondata.vhdx is never created, confirming the VM never initializes.

Additional Notes
This appears to be the same misclassification bug reported in #25136, #27316, #32004, and #42227. CoworkVMService is confirmed running and all virtualization features are enabled. The issue is on Anthropic's side (incorrect hardware classification), not a user configuration problem.

Error Messages/Logs

Steps to Reproduce

Preflight Checklist

  • [x] I have searched existing issues and this is related to known bugs #25136, #27316, #32004, #42227
  • [x] I am using the latest version of Claude Desktop

What's Wrong?

Cowork tab shows "Virtual Machine Platform not available" and prompts to enable the feature and restart. Restarting does not resolve the issue.

The log at %APPDATA%\Claude\logs\cowork_vm_node.log shows the following pattern repeating on every session, with the VM never progressing past this check:

2026-04-17 11:27:42 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...
2026-04-17 11:52:14 [info] [VM] Loading vmClient (TypeScript) module...
2026-04-17 11:52:14 [info] [VM] Module loaded successfully
2026-04-17 12:07:08 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle...

Environment

  • Claude Desktop: v1.3109.0.0 (MSIX, installed from claude.com/download)
  • OS: Windows (details below)
  • CoworkVMService: Running
  • Virtual Machine Platform: Enabled
  • SignatureKind: Developer

Steps to Reproduce

  1. Install Claude Desktop v1.3109.0.0 (MSIX) from claude.com/download
  2. Enable Virtual Machine Platform in Windows Features
  3. Restart computer
  4. Open Claude Desktop and navigate to the Cowork tab
  5. Observe "Virtual Machine Platform not available" error

Expected Behavior
Cowork should detect that virtualization is enabled and successfully initialize the VM workspace.

Actual Behavior
Cowork repeatedly classifies the VM configuration as yukonSilver not supported (status=unsupported) and never downloads or initializes the VM bundle. The error persists after multiple restarts. sessiondata.vhdx is never created, confirming the VM never initializes.

Additional Notes
This appears to be the same misclassification bug reported in #25136, #27316, #32004, and #42227. CoworkVMService is confirmed running and all virtualization features are enabled. The issue is on Anthropic's side (incorrect hardware classification), not a user configuration problem.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude Sonnet 4.6

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_

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