[BUG] CoworkVMService crashes with 'Incorrect function' on Windows 11 Pro 25H2 Build 26200 (v1.1.5749)

Bug Description

CoworkVMService immediately crashes with "Incorrect function" (service-specific error) on Windows 11 Pro 25H2 Build 26200. The VM bundle downloads successfully ("All files ready") but the service binary (cowork-svc.exe) fails to initialize.

Environment

• OS: Windows 11 Pro 25H2 (Build 26200.7922)
• Claude Desktop: v1.1.5749.0 (MSIX)
• CPU: x64
• WSL: 2.5.9.0, Kernel 6.6.87.2-1
• HyperVisorPresent: True

Windows Features (all enabled)

• VirtualMachinePlatform: Enabled
• Microsoft-Hyper-V: Enabled
• Microsoft-Hyper-V-All: Enabled
• HypervisorPlatform: Enabled
• Microsoft-Windows-Subsystem-Linux: Enabled

Services (all running)

• vmcompute: Running
• vmms: Running
• hns: Running
• CoworkVMService: Stopped (crashes on start)

User is in Hyper-V Administrators group: Yes

Error

Windows System Event Log (Event ID 7024):

The Claude service terminated with the following service-specific error: Incorrect function.

Also observed DCOM Event 10016:

The application-specific permission settings do not grant Local Activation permission 
for the COM Server application with CLSID {2593F8B9-4EAF-457C-B68A-50F6B8EA6B54} 
and APPID {15C20B67-12E7-4BB6-92BB-7AFF07997402} 
to the user AMER\HP ZBOOK SID (S-1-5-21-205957447-2577333058-211944522-1002)

Steps to Reproduce

1. Install Claude Desktop v1.1.5749 on Windows 11 Pro Build 26200
2. Enable Hyper-V, VirtualMachinePlatform, HypervisorPlatform
3. Open Claude Desktop → Cowork
4. Bundle downloads successfully ("All files ready in vm_bundles\claudevm.bundle")
5. CoworkVMService starts and immediately crashes with "Incorrect function"

cowork_vm_node.log (relevant section)

[info] rootfs.vhdx.zst checksum validated
[info] [downloadVM] Saved compressed rootfs.vhdx to cache
[info] vmlinuz.zst checksum validated
[info] [downloadVM] Saved compressed vmlinuz to cache
[info] initrd.zst checksum validated
[info] [downloadVM] Saved compressed initrd to cache
[info] All files ready in C:\Users\HP ZBOOK\AppData\Roaming\Claude\vm_bundles\claudevm.bundle
[info] [VM] Loading vmClient (TypeScript) module...
[info] [VM] Module loaded successfully

The Node.js vmClient module loads but never proceeds — the service pipe/socket never responds because cowork-svc.exe has already crashed.

What I've Tried (none resolved the crash)

1. DCOM permission fix: Added user SID and app container SID to LaunchPermission for APPID {15C20B67-12E7-4BB6-92BB-7AFF07997402} — DCOM 10016 may be resolved but service still crashes
2. Enabled HypervisorPlatform Windows feature + reboot
3. Added user to Hyper-V Administrators group + reboot
4. Deleted vm_bundles and claude-code-vm folders for clean rebuild
5. Restarted HNS + vmcompute services, flushed DNS
6. Windows Defender exclusions for Claude WindowsApps and AppData paths
7. Copied cowork-svc.exe out of WindowsApps to bypass MSIX sandbox — still crashes
8. Fixed EXDEV cross-device rename errors (TEMP was on D:, AppData on C:) — bundle now downloads successfully
9. Freed disk space (C: was at 162MB, now 29GB free)

Additional Notes

• The TEMP/TMP env vars were originally pointing to D:\Caches\Temp while AppData is on C:, causing EXDEV errors during download. Fixed by changing TEMP to C:\Users\...\AppData\Local\Temp.
• The MSIX sandbox complicates debugging — cowork-svc.exe cannot be launched directly ("Access is denied") and sc.exe config also returns "Access denied" for this MSIX-registered service.
• The service crashes before any HCS/network operations — "Incorrect function" appears to be during early initialization (possibly signature verification or path resolution).

Related Issues

• #30179 (DCOM 10016 blocks CoworkVMService)
• #27652 (HcnCreateNetwork fails on Build 26200)
• #27801 (VM service not running, persists after reboot)
• #30584 (EXDEV cross-device link on MSIX)

@MarshallOfSound — would appreciate any guidance. Happy to provide additional logs or run diagnostic commands.