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Claude Code Issues / #71650

[BUG] Cowork fails with HYPERVISOR_VIRT_DISABLED on Windows 11 Pro ARM64 in Parallels 26 on M3 Pro

Open 💬 0 comments Opened Jun 26, 2026 by jyhirth

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 shows "Virtualization is not available" on Windows 11 Pro ARM64 running
in Parallels Desktop 26.3.3 on Apple Silicon (M3 Pro). All virtualization
prerequisites are correctly configured but HCS cannot create the compute system.

Environment

  • Mac: Apple Silicon M3 Pro
  • Parallels Desktop: 26.3.3 (57507), nested virtualization enabled via prlctl
  • Windows: 11 Pro ARM64
  • Claude Desktop: 1.15962.0

Verified Configuration
| Check | Result |
|---|---|
| prlctl --nested-virt on | ✅ Set successfully |
| Hyper-V (Windows Feature) | ✅ Enabled |
| Virtual Machine Platform | ✅ Enabled |
| Windows Hypervisor Platform | ✅ Enabled |
| hypervisorlaunchtype | ✅ Auto |
| systeminfo Hyper-V | ✅ "A hypervisor has been detected" |
| CoworkVMService | ✅ Running (LocalSystem) |
| vmms | ✅ Running |

Error from cowork_vm_node.log
2026-06-26 14:16:21 [error] [VM:start] VM boot failed: HCS operation failed:

failed to create compute system: HcsWaitForOperationResult failed with HRESULT

0x80370102: {"Error":-2143878910,"ErrorMessage":"The virtual machine could not

be started because a required feature is not installed.","ErrorEvents":

[{"Message":"Cannot create system 'cowork-vm-b863e30a' since Hyper-V is not

installed on the host.","EventId":11008}]}

2026-06-26 14:16:21 [error] [VM:start] HCS error detected, available=true,

missing=[], sentinel=HYPERVISOR_VIRT_DISABLED

Root Cause Assessment
Parallels exposes enough nested virtualization for Windows to report Hyper-V as
active, but the HCS layer cannot create a child VM within the nested environment
on ARM64. This appears to be a nested Hyper-V limitation specific to ARM64.

Additional Notes
The error message directing users to "Enable virtualization in BIOS/UEFI" is
misleading — the issue is nested virtualization on ARM64, not a BIOS setting.
Related to #49997.

Expected Behavior
Cowork should work in Parallels on Apple Silicon with nested virtualization
enabled, or provide a clear error explaining the ARM64/nested virt limitation

What Should Happen?

Expected Behavior
Cowork should work in Parallels on Apple Silicon with nested virtualization
enabled, or provide a clear error explaining the ARM64/nested virt limitation

Error Messages/Logs

Steps to Reproduce

Environment

  • Mac: Apple Silicon M3 Pro
  • Parallels Desktop: 26.3.3 (57507), nested virtualization enabled via prlctl
  • Windows: 11 Pro ARM64
  • Claude Desktop: 1.15962.0

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

1.15962.0

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_

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