Mastercam X72022 Virtual Usb Bus Error 39 Fix – Must Watch

Title: The Ghost in the Bus

Arjun hated error codes. Not because they were complicated, but because they were liars. Error 39 on his Mastercam X72022 workstation read: “Windows cannot load the device driver for this hardware. The driver may be corrupted or missing.”

But Arjun knew the driver was fine. He’d reinstalled it eleven times.

The problem was the Virtual USB Bus. Mastercam’s new X72022 update required a hypervisor-level USB bridge to talk to his five-axis milling machine. It created a “ghost bus”—a fake USB highway inside the RAM—to shave microseconds off toolpath calculations. And tonight, that ghost had a flat tire.

It started during a 3D HST toolpath simulation. The screen froze, then vomited yellow triangles. Then: Code 39.

Arjun rubbed his eyes. The prototype impeller for the Mars coolant pump was due in nine hours. Without the virtual bus, Mastercam couldn’t see the machine’s hardware dongle. No dongle, no G-code.

He tried the usual exorcisms:

• sfc /scannow → “No integrity violations.” (Liar.)
• DISM /restorehealth → “Component store is repairable.” (Fix nothing.)
• Uninstall/reinstall the Virtual USB Bus driver → “Error 39.” (Circular madness.)

At 2:17 AM, Arjun opened Regedit—the forbidden forest. He navigated to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\USB\VID_0000&PID_0002\Device Parameters

There it was. A stray UpperFilters key with a value that wasn’t a driver. It was a timestamp: 2022-01-01T00:00:00Z. Someone at Mastercam, likely hungover on New Year’s Eve 2021, had hard-coded a filter that expired exactly at midnight, January 1st, 2026.

It wasn’t a driver problem. It was a calendar bomb.

Arjun deleted the UpperFilters key. He deleted the companion LowerFilters key for good measure. Then he opened Device Manager, right-clicked the “Mastercam X72022 Virtual USB Bus,” and selected Update Driver → Browse → Let me pick → Generic USB Hub. mastercam x72022 virtual usb bus error 39 fix

Windows hiccupped. The yellow triangle turned into a green plug icon.

He launched Mastercam. The dongle light blinked. The toolpath regenerated.

At 2:43 AM, the five-axis spindle whirred to life. The impeller began to take shape from a block of 6061 aluminum.

Arjun saved the registry fix as a .reg file and named it: NoMoreGhosts.reg

Then he wrote a single sticky note for the morning shift: “If Error 39 returns, delete UpperFilters. Also, check your CMOS battery. Time bombs love dead clocks.”

The virtual bus ran clean for the next three years. But Arjun never trusted a virtual USB port again. A ghost highway is still a highway—and every highway has a hidden off-ramp.

The "Virtual USB Bus Error 39" in Mastercam (typically appearing for older versions like X7 or when using virtual licensing/HASP tools on modern Windows) generally indicates that Windows has blocked a driver from loading because it doesn't meet security standards or has a corrupted registry entry .

The most effective fixes involve disabling Windows Core Isolation or cleaning the Registry. 1. Disable Memory Integrity (Most Likely Fix)

Modern Windows security features like Core Isolation (Memory Integrity) often block the older "MultiKey" or virtual USB bus drivers used by legacy software because they are not digitally signed to modern standards .

Action: Go to Windows Security > Device Security > Core Isolation details. Step: Toggle Memory Integrity to Off . Title: The Ghost in the Bus Arjun hated error codes

Restart: You must restart your PC for this to take effect. This is the primary reason why drivers that worked on Windows 7 fail on Windows 10/11 . 2. Remove Corrupted Registry Filters

If Windows still cannot load the driver after disabling security features, "UpperFilters" or "LowerFilters" entries in the registry may be blocking the USB class .

Registry Path: Navigate to:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\36FC9E60-C465-11CF-8056-444553540000 .

Action: In the right-hand pane, look for UpperFilters or LowerFilters. If they exist, right-click and Delete them .

Warning: Back up your registry before making changes. After deleting these, restart your computer to force Windows to re-enumerate the USB stack . 3. Reinstall Virtual USB Bus Drivers

If the above steps fail, the driver file itself may be "Bad Image" or improperly registered. How to Fix USB Error Code 39 In Windows 10/8/7 [Tutorial]

After deleting the value, close the Registry Editor and restart the computer to see if the issue is resolved. YouTube·MDTechVideos

2.1 Manual driver removal

1. Device Manager → View → Show hidden devices.
2. Under System devices, right-click Virtual USB Bus → Uninstall device.
   • Check "Delete the driver software for this device" if available.
3. Also uninstall any Aladdin HASP, Sentinel HASP, or SafeNet entries under Universal Serial Bus controllers or Software devices.

Part 3: The Master Fix – Resolving Code 39 for Virtual USB Bus

This solution works for Mastercam X7, 2019, 2020, 2021, and 2022. The steps are identical, but driver names vary slightly by version.

Step 4: Reinstall the Correct Virtual USB Bus Driver

Now you need a clean installation. Do not plug in your HASP yet.

For Mastercam X7 – 2019 (Legacy Driver): sfc /scannow → “No integrity violations

1. Navigate to your Mastercam installation folder, typically: C:\Program Files\Mastercam X7\
2. Find the Drivers or HASP subfolder.
3. Look for HASPUserSetup.exe or Sentinel_Run-time_installer.exe.
4. Right-click → Run as Administrator.
5. Select "Repair" (if available) or "Install".

For Mastercam 2020 – 2022 (Modern Driver):

1. Download the latest Sentinel HASP/LDK Run-time Installer from Thales (formerly SafeNet). Do not use the version on your Mastercam DVD – it’s likely outdated.
2. Run the installer as Administrator.
3. Choose "Complete" installation, then select "Repair".

After installation completes:

• Do NOT restart yet.
• Open Device Manager → Click Action → Scan for hardware changes.
• The "Virtual USB Bus" should reappear without a yellow exclamation mark.

Preliminary Steps (Do These First)

Before diving into advanced fixes, run these quick checks:

1. Run as Administrator – Right-click Mastercam launcher → Properties → Compatibility → Check "Run this program as administrator."
2. Disable Secure Boot (temporarily) – Enter BIOS/UEFI and disable Secure Boot. Some virtual bus drivers require this.
3. Uninstall recent Windows updates – KB5004237, KB5013942, and KB5026361 have broken virtual USB drivers for many CAM applications.

If the error persists, proceed step-by-step.

5. Prevention & Long-Term Stability

Once resolved, prevent recurrence:

• Block Windows from updating the HASP driver automatically via Group Policy or wushowhide.diagcab (Microsoft’s show/hide updates tool).
• Do not run Mastercam driver installers as compatibility mode (Windows 7/8). Use normal Admin rights.
• If you dual-boot or use VMs, do not share the USB controller with the VM while Mastercam is running.
• After Windows feature updates (22H2, 23H2, etc.), reapply test signing (bcdedit /set testsigning on).

1. Understanding Error 39: Why It’s Not a Normal Driver Failure

Standard driver errors (Code 31, 32) often resolve by reinstalling. Error 39 is different:

• It appears even after fresh driver installation.
• The driver file (vusbbus.sys) exists and is signed.
• The device fails during driver stack initialization, not during loading.

The X7-Specific Fix:

1. Open Command Prompt as Administrator.
2. Type the following commands, pressing Enter after each:

   bcdedit /set testsigning on
   bcdedit /set nointegritychecks on
   

3. Restart your PC.
4. You will see "Test Mode" watermark in the bottom-right corner of your desktop – this is normal and required for X7.
5. Reinstall the Virtual USB Bus driver following Steps 1–5 above.

To disable Test Mode later (if you stop using X7): Run the same commands but replace on with off and restart.

Step 3: Delete Stale HASP Driver Files

Even after uninstalling, old driver files may linger.

1. Open File Explorer and navigate to:

   C:\Windows\System32\drivers\
   

2. Look for and delete (or rename to .OLD) the following files if they exist:

   • hardlock.sys
   • hasplms.sys
   • aksdf.sys
   • aksusb.sys
   • vusbbus.sys (This is the main Virtual USB Bus driver)

3. Also check:

   C:\Windows\SysWOW64\drivers\
   

   (Delete the same files if found).