[BUG] VM reports hardware_virt+gisabled after auto=update to v1.1.3918 --- was working fine on v1.1.3830

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?

Title: [BUG] VM reports hardware_virt_disabled after auto-update to v1.1.3918 — was working on v1.1.3830

Preflight Checklist

I have searched existing issues and this hasn't been reported yet
This is a single bug report
I am using the latest version of Claude Desktop

What's Wrong?
After the Claude desktop app auto-updated from v1.1.3830 to v1.1.3918 on Feb 20, 2026, the VM (yukonSilver) stopped starting entirely. It reports hardware_virt_disabled even though hardware virtualization is enabled and the VM was running perfectly on the prior version just hours before.
The VM successfully started multiple times on v1.1.3830 (last success at 6:07 PM on Feb 20). The app auto-updated to v1.1.3918 at 10:48 PM. From the first launch on the new version at 11:12 PM onward, every VM start attempt logs [startVM] VM not supported (win32/x64), skipping. No system, BIOS, or Hyper-V changes were made between the working and broken states.
Hyper-V virtual switches (Default Switch and cowork-vm-vnet) remain active on the system, confirming virtualization is still enabled at the OS and hardware level.
Environment

Windows 11 Pro 25H2 (Build 26200)
Intel i7-1360P (16 cores, VT-x enabled)
15.69 GB RAM
Claude Desktop v1.1.3918 (MSIX from Microsoft Store)
VM SDK v2.1.49

Steps to Reproduce

Have a working Claude Desktop VM on v1.1.3830
Allow auto-update to v1.1.3918
Attempt any Cowork/VM task — VM refuses to start

Expected Behavior
VM should start as it did on v1.1.3830.
Attachments

PDF report with full log analysis and timeline (attached)
Original Claude log bundle ZIP (attached)

Related: #25914 (similar HCS/VM failure on same Windows build 26200)

What Should Happen?

it Should work after Claude does its auto update to the next version

Error Messages/Logs

iy is in zip files

Steps to Reproduce

none it was auto update then on next boot failed

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

v1.1.3918

Claude Code Version

v1.1.3918

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

Claude-logs-2026-02-21T05-13-15-057Z.zip