Mastercam X72022 Virtual Usb Bus Error - 39 Fix

UpperFilters/LowerFilters registry entries are corrupted. Method 1: Disable Core Isolation (Memory Integrity)

Mastercam uses a software protection key (HASP or NetHASP) that requires a virtual USB bus driver to communicate with the license manager. When Windows displays Error 39 in the Device Manager, it is usually triggered by one of the following:

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

Select from the left-hand or main dashboard menu. Click on the Core isolation details link. Locate Memory integrity and toggle the switch to Off . Restart your computer for the changes to take effect. Step 2: Enable Test Signing Mode mastercam x72022 virtual usb bus error 39 fix

Windows blocks the driver because it cannot verify its digital signature, preventing Mastercam from launching. This guide provides actionable steps to resolve Error 39 across Mastercam versions X7 through 2022. Root Causes of Error 39

Download the latest Sentinel HASP/LDK Windows GUI Runtime from the Thales Group website or the latest emulator package you are using. Restart your computer and install the driver package.

Recent Windows 10 or Windows 11 updates enforcing stricter driver signing policies. Step 1: Disable Windows Memory Integrity (Core Isolation) UpperFilters/LowerFilters registry entries are corrupted

The most common solution for modern Windows systems (10/11) is disabling Memory Integrity

Bad registry entries corrupt the driver stack. Step 1: Disable Core Isolation and Memory Integrity

If the driver file itself is corrupted, you must clean it out of the Device Manager and the registry before reinstalling it. Clean Device Manager Press Windows Key + X and select . Click View at the top menu and select Show hidden devices . Error 39 is different: Select from the left-hand

The "Error Code 39" for the Mastercam Virtual USB Bus typically occurs because Windows security features, specifically , 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)

A: Many antivirus programs flag Virtual USB drivers as potential threats because they modify system-level behavior. Temporarily disable your antivirus during installation, and add an exception for the Virtual USB driver folder to prevent future deletions.

If you've tried all of the above and error 39 persists, consider that the issue might be hardware-related. Test your physical USB dongle or emulator on another computer to confirm it works. If it does, the issue lies with your Windows configuration—and a Windows repair installation or clean Windows setup may ultimately be the solution.