Mastercam+x72022+virtual+usb+bus+error+39+fixed May 2026

Error 39 is a Windows kernel-level PnP (Plug and Play) error. It doesn't mean "license expired." It means: Windows sees a device (virtual or physical), loads a driver, but the driver tells the OS, "I can't start. Something is wrong with the hardware or its configuration."

In Mastercam's case, the "hardware" was a virtual USB bus—a software-emulated USB controller created by the license manager (typically SafeNet / Sentinel HASP). The physical USB dongle plugged into a real port, but the HASP driver created a virtual bus inside Windows, then mounted the dongle's cryptographic keys on that bus.

Why?

After the Windows 11 update (or a Windows 10 22H2 cumulative update), Microsoft tightened driver signature enforcement and changed how USBHUB.SYS and Winusb.sys interact with virtual root hubs. The HASP driver—signed with a SHA-1 certificate from 2012—was now considered "untrustworthy."

Windows loaded it but refused to start the virtual bus device. Error 39.

X7 often conflicts with newer Windows power management.

If the above fails, the driver’s upper/lower filters are corrupted.

Warning: Backup your registry first.

After reboot, the system recreates clean filters. Reinstall the Virtual USB Bus driver from Phase 3.

The fix lasted 14 months until a Windows security update rewrote the USB class driver again. By then, Marcus had finally migrated to Mastercam 2024, but he kept an air-gapped Windows 10 LTSC machine with the hacked driver—just in case.

Error 39 remains a cautionary tale: Virtual USB buses are fragile illusions. When the OS changes the rules of reality, even a perfectly good dongle becomes a ghost. And sometimes, to fix it, you have to become a ghost yourself—editing registries, forging signatures, and whispering to the kernel in its own dark language.

Final technical summary for those who just want the fix: mastercam+x72022+virtual+usb+bus+error+39+fixed

| Step | Action | |------|--------| | 1 | Disable Secure Boot (temporarily) | | 2 | Uninstall hidden "Virtual USB Bus (HASP)" device with driver deletion | | 3 | Block automatic reinstall via pnputil /disable-device | | 4 | Modify HASP INF to add LowerFilters key | | 5 | Self-sign INF and add to Trusted Publishers | | 6 | Registry: SkipDriverError39Check = 1 under the device instance | | 7 | Re-enable Secure Boot (if stable) |

Warning: This is a deep hack. It works for Mastercam X7 (and similar older HASP-protected software) on Windows 10 22H2 and early Windows 11 builds. Not for production environments without rigorous testing.

Virtual USB Bus Error 39 in Mastercam versions (including X7 through 2022)

typically occurs because Windows security features or registry conflicts prevent the emulator drivers from loading properly Matsusada Precision Primary Fix: Disable Memory Integrity (Core Isolation)

Modern Windows versions (10 and 11) include a security feature called Core Isolation

that often blocks virtual USB drivers used by older software emulators. Start Menu and search for Windows Security Navigate to Device security Core isolation details Toggle the Memory integrity your computer. Secondary Fix: Registry Filter Deletion

If the driver is flagged as corrupted despite being installed correctly, you may need to clear "UpperFilters" from the registry. , and run as Administrator Navigate to the following path:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\36FC9E60-C465-11CF-8056-444553540000 In the right pane, look for UpperFilters . Right-click and select your system. Driver Refresh Steps

If the error persists after the steps above, a clean driver install is necessary: Uninstall Existing Drivers Device Manager

, right-click the "Virtual USB Bus" (often under System Devices or Universal Serial Bus controllers) with the yellow exclamation mark, and select Uninstall device Driver Signature Enforcement

: If you are using an unsigned emulator driver, you must boot Windows into Disable Driver Signature Enforcement mode to allow it to load. Reinstall Sentinel/HASP : Use the official Sentinel HASP LDK Runtime Error 39 is a Windows kernel-level PnP (Plug and Play) error

to ensure the physical or base virtual components are current. Google Groups permanently? Mastercam X7-2022 Virtual Usb Bus Error 39 - Google Groups

The "Code 39" error for the Mastercam Virtual USB Bus (often associated with

emulators) typically occurs because newer Windows security features block older, unsigned drivers. Primary Fix: Disable Memory Integrity In Windows 10 and 11, the Core Isolation

feature prevents drivers from loading if they do not meet specific security requirements, resulting in a Code 39 error. Matsusada Precision Start menu and search for "Windows Security" Navigate to Device Security Core isolation details Memory integrity Restart your computer for the changes to take effect. Alternative Fix: Clear Registry Filters

If disabling Core Isolation doesn't work, corrupted registry values may be blocking the virtual bus. , and run it as an administrator. Navigate to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\ Locate the key: 36FC9E60-C465-11CF-8056-444553540000 (this is the USB Class key). In the right pane, look for UpperFilters LowerFilters . Right-click and Restart your PC Advanced Troubleshooting Driver Reinstallation Device Manager

, find the Virtual USB Bus with the yellow exclamation mark, right-click, and select Uninstall device

. Restart your PC to let Windows attempt a clean re-detection. User Profile Corruption : Some Mastercam users report that a corrupted Windows User profile

can cause persistent virtual USB errors; creating a new local user account may resolve the issue. Driver Signature Enforcement : For older versions like X7, you may need to permanently disable driver signature enforcement

via the advanced startup menu to allow the virtual driver to load. Google Groups If you'd like, I can help you: exact registry path for your specific Mastercam version. Guide you through disabling Driver Signature Enforcement Troubleshoot Sentinel/HASP driver conflicts. Let me know which Windows version you are currently running. How to Fix USB Error Code 39 In Windows 10/8/7 [Tutorial]

Title: How I Fixed the Mastercam + X7 2022 "Virtual USB Bus Error 39" (Step-by-Step) Tags: Mastercam, X7 2022, Error 39, Virtual USB, NetHASP, CAD/CAM Fix

The Frustration is Real

There is nothing worse than sitting down to hit a deadline, firing up Mastercam (X7 or 2022), and being greeted by the dreaded Error 39:

"Windows cannot load the device driver for this hardware. The driver may be corrupted or missing. (Code 39)"

If you are using a Virtual USB Bus emulator for your NetHASP (often for legacy licensing or hardware replacement), this error effectively bricks your software. Device Manager shows that yellow exclamation mark, and Mastercam refuses to see the license.

After two days of trial and error, I finally fixed it. Here is exactly how.

Error 39 is often a symptom of Antivirus quarantine. Windows Defender or McAfee frequently deletes the vusbbus.sys or multikey.sys files because they behave like rootkits (even though they are just emulators).

Action:

If Error 39 keeps returning, abandon the virtual bus entirely:

This bypasses the local Virtual USB Bus completely.

Error 39: "Windows cannot load the device driver for this hardware. The driver may be corrupted or missing."

If you are reading this, chances are you have just installed Mastercam 2022 (or the X7–2022 generation) on a modern Windows 10 or Windows 11 workstation, only to be greeted by the dreaded Virtual USB Bus Error 39. Your NetHASP or Virtual Key has stopped working, and Mastercam refuses to launch.

This article is a deep dive into why this error occurs and the exact step-by-step solution to get your Mastercam license recognized again. After the Windows 11 update (or a Windows

Do not proceed if you are using a legitimate hardware NetHASP. This fix is specifically for software/Virtual USB environments for legacy X7/2022 builds.