Mastercam X72022 Virtual Usb Bus Error 39 - Fix
If you are using a virtual simulator (commonly searched as "virtual usb bus" or "NetHASP"), the Error 39 often stems from the emulator software itself conflicting with the actual Sentinel drivers.
Summary of Fix:
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 "Error Code 39" for the Mastercam Virtual USB Bus typically occurs because Windows security features, specifically Core Isolation, block the driver from loading. This error indicates that the driver is corrupted, missing, or more commonly in recent Windows versions, incompatible with modern memory protection. Primary Fix: Disable Core Isolation (Memory Integrity)
Most modern Windows 10 and 11 systems block older or unsigned drivers via a feature called Memory Integrity. Open Windows Security from the Start menu. Navigate to Device security > Core isolation details. Toggle Memory integrity to Off. Restart your computer for the change to take effect. Secondary Fix: Registry Edit (DeviceGuard)
If you cannot toggle Memory Integrity in settings, you can force it off via the Windows Registry Editor:
Search for regedit in the Start menu and run as administrator.
Navigate to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\DeviceGuard\Scenarios\HypervisorEnforcedCodeIntegrity. Set the Enabled value to 0. Restart your system. Additional Troubleshooting Steps Mastercam X7-2022 Virtual Usb Bus Error 39 - Google Groups
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 . mastercam x72022 virtual usb bus error 39 fix
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 .
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
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 If you are using a virtual simulator (commonly
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)
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 —
If you need a stable, legal alternative, upgrade to a modern Mastercam version with native license manager (no virtual USB bus needed).
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. Summary of Fix:
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:
The "Code 39" error for the Virtual USB Bus (often associated with
drivers) in Mastercam typically indicates that Windows cannot load the driver because it is corrupted, missing, or blocked by security features. Microsoft Learn Primary Fixes for Error Code 39 Disable Core Isolation (Memory Integrity)
: This is the most common cause on Windows 10 and 11. Newer Windows security features block older virtual USB drivers. Windows Settings Update & Security Privacy & security in Win 11). Windows Security Device Security Core isolation details and toggle Memory integrity your computer. Registry Modification (Hypervisor Enforced Code Integrity)
: If you cannot toggle Memory Integrity in settings, you can disable it via the Registry Editor. , and hit Enter. Navigate to:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\DeviceGuard\Scenarios\HypervisorEnforcedCodeIntegrity Delete Registry UpperFilters/LowerFilters
: Corruption in these keys can prevent USB drivers from loading.
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\36FC9E60-C465-11CF-8056-444553540000 In the right pane, find UpperFilters LowerFilters , right-click, and select your system. Additional Troubleshooting Mastercam X7-2022 Virtual Usb Bus Error 39 - Google Groups
Mastercam X7-2022 virtual USB bus error 39 typically occurs when Windows prevents a third-party driver from loading due to modern security features or registry corruption. This error is often associated with "MultiKey" or Aladdin HASP drivers used for software licensing. Primary Fix: Disable Core Isolation (Memory Integrity) The most common cause for Error 39 on Windows 10 and 11 is Memory Integrity
, a security feature that blocks drivers it deems incompatible. Matsusada Precision Windows Settings and navigate to Privacy & security (Win 11) or Update & Security Windows Security Device security Core isolation details Memory integrity Restart your computer for the changes to take effect. Alternative Fix: Registry Editor (Lower/Upper Filters)
If disabling security features does not work, corrupted registry values may be blocking the USB bus. , and press Enter. Navigate to the following path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\ Locate the specific folder for USB Controllers: 36FC9E60-C465-11CF-8056-444553540000 In the right-hand pane, look for UpperFilters LowerFilters Right-click and these values. Restart your PC Driver Specifics for Virtual USB Bus How to Fix USB Error Code 39 In Windows 10/8/7 [Tutorial]
Standard driver errors (Code 31, 32) often resolve by reinstalling. Error 39 is different: