[BUG] CoworkVMService causes BSOD (HYPERVISOR_ERROR 0x00020001) on AMD Ryzen 9 5950X — hvax64.exe unhandled page fault every startup

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?

Every time CoworkVMService starts, Windows crashes with BSOD bugcheck 0x00020001 (HYPERVISOR_ERROR). The crash is 100% reproducible and has occurred 10 times across multiple days. The Windows Error Reporting name in every crash is:

NOBLOB_HYPERVISOR_ERROR_Unhandled_PageFault_100003939fe_IMAGE_hvax64.exe
CoworkVMService launches hvax64.exe, which immediately throws an unhandled page fault and crashes the entire system. This happens on every restart of the service without exception.

On my Macbook Pro, everything works fine. This is only on Windows.

What Should Happen?

CoWork and anything relating to Claude should just work and not cause PC to crash.

Error Messages/Logs

NOBLOB_HYPERVISOR_ERROR_Unhandled_PageFault_100003939fe_IMAGE_hvax64.exe

Steps to Reproduce

1. Enable Virtual Machine Platform in Windows Optional Features
2. Install Claude Desktop on Windows 11 Pro with AMD Ryzen 9 5950X
3. CoworkVMService starts automatically on boot or when opening Claude Desktop
4. System BSODs after some time happens randomly between a few seconds to maybe a couple hours— every time, without fail

Claude Model

Not sure / Multiple models

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.161

Platform

Other

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

things already tried (did not fix)

Disabled Hyper-V completely
Disabled Windows Hypervisor Platform
Disabled aehd.sys (Android emulator driver)
Disabled IOMMU in BIOS
Disabled XMP/EXPO memory profile
Updated BIOS to latest (5302)
Ran Windows memory diagnostic (passed)
Ran SFC and DISM (no errors found)

060226-11593-01.dmp