VIETNAM TECHNICAL VIEW
The "Error Code 39" in Mastercam (typically related to the Virtual USB MultiKey or HASP drivers) usually indicates that Windows cannot load the device driver because it is either corrupted, missing, or blocked by security features. This is a common issue on Windows 10 and 11 due to enhanced security protocols like Memory Integrity. Core Solutions to Fix Error 39
The most effective fix for this specific Mastercam error involves adjusting Windows security settings or cleaning up registry filters. 1. Disable Core Isolation (Memory Integrity)
This is the most frequent cause for Virtual USB drivers failing to load. Windows security blocks drivers it deems "incompatible" with memory protection. Open the Start menu and search for Windows Security. Navigate to Device security > Core isolation details. Toggle Memory integrity to Off. Restart your PC for the changes to take effect. 2. Delete Upper/Lower Filters in Registry
If the driver itself is corrupted, Windows may have "stuck" filters in the registry preventing proper communication.
Press Win + R, type regedit, and hit Enter to open the Registry Editor.
Navigate to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\36fc9e60-c465-11cf-8056-444553540000 (This is the standard class for USB controllers).
In the right pane, look for UpperFilters and LowerFilters. If they exist, right-click and Delete them. Restart your computer. 3. Reinstall Virtual USB / HASP Drivers How to Fix USB Error Code 39 In Windows 10/8/7 [Tutorial]
Important: Back up system restore point and export registry keys you modify.
A. Restart and simple checks
B. Reinstall/repair license drivers (Vendor-specific)
Examples:
C. Remove corrupted drivers and reinstall
D. Repair Windows driver store and system files
E. Check and clean registry filter drivers (UpperFilters/LowerFilters)
F. Reinstall Mastercam license components mastercam+x72022+virtual+usb+bus+error+39+fixed
G. Check services and permissions
H. Antivirus/Driver signature enforcement
I. If driver files exist but get blocked by Windows driver store corruption
J. Reinstallation of Windows USB Controller drivers
K. Last resorts
| Mastercam Version | Known Issue with Error 39 | Best Fix | |-------------------|---------------------------|-----------| | X7 (2013) | Windows 10 20H2+ blocks driver | Step 4 (Test Mode) + Step 3 (Registry) | | X9 (2015) | Driver signing expiry | Step 5 (Replace vusbbus.sys) | | 2018 | Conflict with USB 3.0 controllers | Step 2 + Disable xHCI in BIOS | | 2020 | Memory Integrity blocks | Step 1 (Core Isolation OFF) | | 2022 | Windows 11 native incompatibility | Step 6 (Hardware ID injection) |
If you are still seeing Code 39, you may need to roll back the specific Windows Update (KB5028185 or KB5030211 are known offenders for breaking virtual USB stacks).
Have a different error code? Let me know in the comments. Good luck machining!
Disclaimer: This post is for educational purposes regarding legacy software compatibility. Ensure you own a valid Mastercam license.
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: The "Error Code 39" in Mastercam (typically related
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
to ensure the physical or base virtual components are current. Google Groups permanently? Mastercam X7-2022 Virtual Usb Bus Error 39 - Google Groups
The Virtual USB Bus Error 39 in Mastercam (typically versions X7 through 2022) is a common driver signature or compatibility issue. It occurs because Windows cannot load the virtual device driver required for the software's emulator (often used for bypasses or specific hardware keys) because it isn't digitally signed or is being blocked by security features. Core Causes of Error 39
Driver Signature Enforcement: Windows 10 and 11 block drivers that aren't verified by Microsoft.
Memory Integrity (HVCI): A Windows Security feature that prevents "untrusted" drivers from loading into high-security memory.
Corrupt Registry Entries: Leftover keys from previous installations or failed emulator setups. Step-by-Step Solutions 1. Disable Windows Driver Signature Enforcement
This is the most common fix for Error 39. Windows requires a special boot mode to allow these virtual drivers to load. Click Start > Settings > Update & Security > Recovery. Under Advanced startup, click Restart now.
Once the PC restarts, navigate to: Troubleshoot > Advanced options > Startup Settings > Restart.
After restarting again, a list of options will appear. Press 7 or F7 to Disable driver signature enforcement.
Once Windows boots, try reinstalling the virtual USB driver or launching Mastercam. 2. Turn Off Memory Integrity (Core Isolation)
Modern Windows security often blocks virtual USB emulators even if signature enforcement is off. Open Windows Security (search for it in the Start menu). Go to Device security > Core isolation details. Toggle Memory integrity to Off. Restart your computer. 3. Update or Reinstall the MultiKey/Emulator Driver Fixes — concrete steps (ordered: safest → more
If the driver itself is outdated, it will trigger Error 39 regardless of settings. Open Device Manager (Right-click Start > Device Manager).
Look for Universal Serial Bus controllers or System devices.
Locate the "Virtual USB Bus" or "MultiKey" entry with the yellow exclamation mark.
Right-click it, select Uninstall device, and check "Delete the driver software for this device."
Run your emulator setup script (usually install.bat or setup.exe provided with your specific version) as an Administrator. 4. Registry Cleanup
If the error persists, old registry keys might be pointing to the wrong driver path. Press Win + R, type regedit, and hit Enter.
Navigate to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\MultiKey (or the specific emulator key). Ensure the paths match your current installation directory.
Note: Always back up your registry before making manual changes. Verification
After applying these fixes, check the Device Manager again. The "Virtual USB Bus" should appear under "System devices" or "USB controllers" without any warning icons.
It looks like you have provided a search query or a title for a technical fix regarding Mastercam X7 2022 and a specific Windows error.
Here is the information and solution based on that query:
Problem: You are trying to run Mastercam X7 (or a similar version) on Windows, but the software fails to launch or cannot find the SIM (license), displaying "Virtual USB Bus Error 39".
Cause: This error is caused by the Mastercam USB Emulator (the "virtual USB" driver used to simulate the hardware license key). Specifically, Error 39 in Windows Device Manager means that the driver installed correctly, but Windows cannot load the specific driver file (usually due to digital signature requirements or a corrupted registry entry).
