Error 39 Virtual USB Bus Error in Mastercam X7 2022: A Comprehensive Fix
Are you encountering the frustrating Error 39 Virtual USB Bus error while using Mastercam X7 2022? This issue can disrupt your workflow and hinder productivity. In this response, we will provide a step-by-step guide to resolve the Virtual USB Bus Error 39 in Mastercam X7 2022.
What is Error 39 Virtual USB Bus Error?
The Error 39 Virtual USB Bus error typically occurs when Mastercam X7 2022 fails to communicate with the USB dongle or license manager. This issue may arise due to a corrupted driver, outdated software, or a conflict with other system applications.
Causes of Error 39 Virtual USB Bus Error:
Step-by-Step Fix for Error 39 Virtual USB Bus Error:
Conclusion:
By following these steps, you should be able to resolve the Error 39 Virtual USB Bus error in Mastercam X7 2022. If the issue persists, it is recommended to contact Mastercam support or a qualified technical expert for further assistance.
Additional Tips:
The Virtual USB Bus Error 39 in Mastercam (spanning versions from X7 to 2022) typically indicates that Windows cannot load the virtual device driver, often flagging it as corrupted or missing. This issue is frequently caused by modern Windows security features like Core Isolation or residual registry filters that block the driver from initializing correctly. Primary Fix: Disable Core Isolation (Memory Integrity)
Most modern Windows 10 and 11 systems include a feature called "Memory Integrity" that prevents unsigned or older drivers from loading. Disabling this is often the most effective solution. Windows 10/11 Steps: Open the Start menu and type "Windows Security". Navigate to Device security on the left sidebar. Click on Core isolation details. Toggle the Memory integrity switch to Off. Restart your computer to apply the changes. Secondary Fix: Registry Editor (Upper and Lower Filters)
If disabling Core Isolation doesn't work, specific registry entries known as "UpperFilters" or "LowerFilters" might be corrupting the USB stack. Press Win + R, type regedit, and hit Enter.
Navigate to the following path:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\36FC9E60-C467-11CF-8056-444553540000
In the right-hand pane, look for UpperFilters or LowerFilters. Right-click them and select Delete. Restart your PC. Alternative Troubleshooting Steps
If the error persists, consider these hardware and driver-specific actions:
The Virtual USB Bus Error 39 in Mastercam versions ranging from X7 to 2022 is primarily caused by Windows security features blocking unsigned or outdated virtual drivers. Primary Fix: Disable Core Isolation
The most effective solution for Windows 10 and 11 users is disabling Memory Integrity, which often prevents the virtual USB bus driver from loading.
Open Windows Settings and navigate to Privacy & security > Windows Security. Select Device security and click on Core isolation details. Toggle the Memory integrity switch to Off. Restart your computer to apply the changes. Secondary Fix: Registry Filter Removal
If the error persists, corrupted registry "filters" may be the culprit. Press Win + R, type regedit, and hit Enter.
Navigate to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\.
Locate the folder corresponding to your USB device (often ends in 36FC9E60). mastercam x72022 virtual usb bus error 39 fix
In the right pane, right-click and Delete the values named UpperFilters and LowerFilters if they exist. Restart your PC. Additional Troubleshooting
Driver Reinstallation: Uninstall the "Virtual USB Bus" or "Sentinel/HASP" driver from Device Manager, then reinstall the latest version from the Mastercam website.
Check for Conflicts: Unplug other USB devices (like cell phones or 3D controllers) before starting Mastercam, as they can cause driver conflicts.
User Profile Corruption: In some corporate environments, a corrupt Windows User Profile has been known to cause this specific error; creating a new profile may resolve it. Mastercam X7-2022 Virtual Usb Bus Error 39 - Google Groups
Comprehensive Guide to Fixing Mastercam Virtual USB Bus Error 39 (X7–2022) Encountering Error Code 39 on the Virtual USB Bus for
(versions X7 through 2022) typically means Windows cannot load the device driver because it is either corrupted, missing, or blocked by modern security features. This often occurs on newer operating systems like Windows 10 and 11, where advanced protections conflict with legacy emulator drivers. 1. Disable Windows Core Isolation (Memory Integrity)
The most common cause for Error 39 in modern Windows environments is a security feature called Core Isolation (Memory Integrity). This feature blocks drivers that do not meet specific security standards, which often includes the virtual USB bus emulators used for Mastercam. Open the Start Menu and type "Windows Security". Navigate to Device Security on the left-hand menu. Click on Core isolation details. Toggle the Memory integrity switch to Off. Restart your computer for the changes to take effect.
2. Registry Fix: Disabling Hypervisor-Enforced Code Integrity
If the UI toggle for Core Isolation is greyed out or does not resolve the issue, you can use the Registry Editor to manually disable the blocking mechanism. Press Win + R, type regedit, and press Enter.
Navigate to the following path:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\DeviceGuard\Scenarios\HypervisorEnforcedCodeIntegrity Find the Enabled value on the right pane. Right-click it, select Modify, and set the Value Data to 0. Restart your PC. 3. Clear Registry Filters (UpperFilters and LowerFilters) How to Fix USB Error Code 39 In Windows 10/8/7 [Tutorial]
To fix the Virtual USB Bus Error 39 in Mastercam (X7 through 2022 versions), you typically need to
address driver integrity issues caused by Windows security features or corrupted registry entries
The most common solution for modern Windows systems (10/11) is disabling Memory Integrity
, which often blocks virtual USB drivers used for licensing. Matsusada Precision 1. Disable Core Isolation (Memory Integrity)
Windows security can block the virtual driver from loading, resulting in Error 39. Windows Security (search for it in the Start menu). Device security Core isolation details Memory integrity
your computer and check the Device Manager to see if the error is gone. 2. Remove "UpperFilters" and "LowerFilters" in Registry
If disabling security doesn't work, corrupted registry values may be preventing the driver from loading. , and press Enter. Navigate to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\ Find the folder: 36FC9E60-C465-11CF-8056-444553540000 In the right pane, look for UpperFilters LowerFilters . Right-click and your computer. 3. Reinstall HASP Drivers
Corrupted drivers are a frequent cause. A clean reinstall is often necessary. How to Fix USB Error Code 39 In Windows 10/8/7 [Tutorial]
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.” Error 39 Virtual USB Bus Error in Mastercam
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:
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.
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 Mastercam virtual USB bus error (Code 39) typically occurs because Windows security features or corrupted registry entries prevent the virtual driver from loading. 1. Disable Core Isolation (Memory Integrity)
Modern Windows security often blocks virtual USB drivers like those used by Mastercam. Disabling this feature is the most common fix. menu and search for Windows Security Device security Core isolation details Memory integrity
your computer and check if the driver loads in Device Manager. Matsusada Precision 2. Remove Corrupted Registry Filters
Corrupted "UpperFilters" or "LowerFilters" can block USB device drivers from starting. , and press Navigate to:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\36FC9E60-C465-11CF-8056-444553540000 In the right pane, look for UpperFilters LowerFilters Right-click and these values if they exist. your computer. 3. Disable Virtualization-Based Security (Registry) Outdated or corrupted Virtual USB Bus driver Incompatible
If you cannot toggle Core Isolation via settings, you can force it off in the registry. Microsoft Learn Registry Editor
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\DeviceGuard\Scenarios\HypervisorEnforcedCodeIntegrity Microsoft Learn 4. Reinstall Virtual USB Drivers
If the error persists, the driver files themselves may be corrupted. Mastercam X7-2022 Virtual Usb Bus Error 39 - Google Groups 24 Jul 2024 —
The Virtual USB Bus Error 39 in Mastercam versions X7 through 2022 typically indicates that Windows cannot load the device driver for the virtual HASP or dongle emulator, often due to a driver being corrupted, missing, or blocked by modern security features. The primary resolution involves disabling Core Isolation (Memory Integrity) in Windows Security or removing specific Registry filters that interfere with driver loading. Primary Cause: Windows Core Isolation
Modern versions of Windows 10 and 11 include a security feature called Memory Integrity (part of Core Isolation). This feature prevents unauthorized code from running in high-security processes but frequently blocks older virtual drivers used by Mastercam emulators. Experts from Matsusada Precision and RT Systems identify this as the leading cause of Code 39 errors for USB-related hardware. How to Fix: Open Windows Security and navigate to Device Security. Click on Core isolation details. Toggle Memory integrity to Off. Restart your computer to apply changes. Secondary Cause: Corrupted Registry Filters
If disabling Core Isolation does not work, the error may stem from corrupted "UpperFilters" or "LowerFilters" in the Windows Registry. These entries can prevent Windows from correctly identifying and loading the virtual USB bus required for Mastercam. Registry Modification: Open regedit (Registry Editor).
Navigate to the relevant device class key. While common for optical drives, similar issues affect virtual USB controllers. According to Microsoft Support, deleting these filters can force Windows to rebuild the driver stack.
Search for UpperFilters and LowerFilters within the USB or Virtual Bus keys and delete them. Restart the machine. Driver Reinstallation and Virtual Key Issues
For virtual keys like MultiKey used in older Mastercam setups, a clean reinstallation of the virtual bus is often necessary. Users on Google Groups have noted that standard Aladin or HASP drivers may fail if bizarre interactions occur with other USB peripherals (like 3D Connexion mice). Resolution Steps:
Uninstall the Virtual Device: In Device Manager, find the device with the yellow exclamation mark (Error 39), right-click, and select Uninstall device.
Scan for Changes: Use the Action > Scan for hardware changes option in Device Manager to let Windows attempt a clean reload.
Update HASP Drivers: Ensure you are using the latest HASP HL driver compatible with your specific Windows version.
The following tutorials provide visual step-by-step guidance on disabling security features and editing the registry to clear Error 39:
A “USB Bus Error 39” in Mastercam X7 (or any software using a virtual USB dongle, like the 2022 version of the HASP/SafeNet emulator) usually means Windows cannot load the virtual device driver because its registry entries are corrupted or another driver is conflicting.
Here’s a focused review of the problem and the most reliable fix:
Before diving into registry edits, perform these quick checks:
If the error persists, proceed.
Standard driver errors (Code 31, 32) often resolve by reinstalling. Error 39 is different:
vusbbus.sys) exists and is signed.Once resolved, prevent recurrence:
wushowhide.diagcab (Microsoft’s show/hide updates tool).bcdedit /set testsigning on).This error became widespread for three main reasons:
Haspnt.sys or hardlock.sys files that the Virtual USB Bus depends on.Important Distinction:
- Error 39 (Virtual USB Bus) → Problem with the driver itself or its registry keys.
- Error 10 (Device cannot start) → Usually a USB port power or physical HASP issue.
- No error, but Mastercam says "No License Found" → HASP driver is working, but the license file is missing.