Cowork "Virtualization is not enabled" error after update — Windows 11 Pro, Hyper-V enabled
Status Fixed / completed
Maintainer reply None cached
Activity 5 comments · opened Feb 21, 2026 · closed Feb 22, 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?
Cowork worked on first launch, then broke after an auto-update.
Error: "Virtualization is not enabled"
System: Windows 11 Pro, ASUS TUF Gaming F15 FX506HE
HypervisorPresent: True
Hyper-V: Enabled
vmcompute: Running
hypervisorlaunchtype: Auto
Tried: Clean install, deleted vm_bundles, cleared LocalCache — issue persists.
What Should Happen?
Cowork should start successfully and allow task execution, as it did on first launch.
Error Messages/Logs
Steps to Reproduce
- Install Claude Desktop on Windows 11 Pro
- Open Cowork tab — works fine on first launch
- Allow Claude Desktop to auto-update
- After update, open Cowork tab
- Error appears: "Virtualization is not enabled"
- Tried: clean reinstall, deleted vm_bundles folder, cleared LocalCache — issue persists
Claude Model
Sonnet (default)
Is this a regression?
Yes, this worked in a previous version
Last Working Version
_No response_
Claude Code Version
Claude Desktop v1.1.3918 (Windows) — Claude Code CLI not installed
Platform
Anthropic API
Operating System
Windows
Terminal/Shell
Terminal.app (macOS)
Additional Information
_No response_
5 Comments
Found 3 possible duplicate issues:
This issue will be automatically closed as a duplicate in 3 days.
🤖 Generated with Claude Code
I have this issue can you investigate if it is indeed a bug or there is anything I can do?
Environment:
OS: Windows 11 Pro 25H2 (Build 26200.7462) — received via standard Windows Update, not Insider Programme
Hardware: Dell Latitude 7400 (physical machine, confirmed not a VM)
Installer: Claude Setup.exe (direct download from claude.ai/download)
Windows Features enabled:
Microsoft-Hyper-V-All ✅
HypervisorPlatform ✅
VirtualMachinePlatform ✅
WSL2 installed with Ubuntu ✅
Services running:
vmms (Running, Automatic)
vmcompute (Running, Manual)
hns (Running, Manual)
Relevant log output from cowork_vm_node.log:
2026-02-21 10:21:44 [info] [cleanupVMBundleIfUnsupported] yukonSilver not supported (status=unsupported), checking for stale bundle... 2026-02-21 10:22:37 [warn] [startVM] VM not supported (win32/x64), skipping
Error shown in UI:
"Virtualization is not enabled. Claude's workspace requires hardware virtualization (Hyper-V). Enable virtualization in your computer's BIOS/UEFI settings, then restart."
This error is misleading — hardware virtualization is confirmed enabled and all required features are active. The issue appears to be yukonSilver incorrectly flagging this win32/x64 environment as unsupported despite full Hyper-V support being present.
main.log content:
platform: win32, arch: x64, version: 1.1.3918
cowork_vm_node.log is never created — VM startup is being blocked before initialization. Same as reported by Alex-Saad: yukonSilver flagged as unsupported on win32/x64.
Closing as duplicate of #27316 which was very rapidly fixed in the v1.1.3963 release
This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.