Install correct driver for your Mastercam version:
: If you are using a legitimate license and HASP key, Mastercam provides a System Inspector Utility
Before installing functional drivers, you must purge the broken components from your system: Press Win + X and select . Scroll down and expand Universal Serial Bus controllers . Locate Mastercam X7-2022 Virtual USB Bus Go to product viewer dialog for this item. (or Virtual USB MultiKey ). mastercam x72022 virtual usb bus error link
| File Name to Find | Action to Take | Notes | | :--- | :--- | :--- | | multikey.sys | Search for and delete this file. | This is a common virtual USB driver file. Its presence can prevent a clean installation. | | mcamvusb.sys | Search for and delete this file. | This is the standard Mastercam virtual USB driver file. | | vusbbus.sys | Search for and delete this file. | This file can also conflict with licensing. | | | Delete the Class Key 36FC9E60-C465-11CF-8056-444553540000 via regedit . | Caution: Back up your registry first. This clears filter drivers that block the USB bus. |
This error typically occurs when Mastercam cannot communicate with its license key, often due to an improperly installed or blocked "Virtual USB Bus Enumerator" driver. This driver is frequently used in older or modified versions of the software to emulate a physical USB HASP security dongle. Common Fixes for "Virtual USB Bus" Errors Install correct driver for your Mastercam version: :
When you install Mastercam, especially versions that may have used emulation tools to simulate a hardware key (a "virtual USB key" or "Multikey driver"), the Windows operating system must recognize this virtual driver.
Understanding the root cause is essential to applying the correct fix. This error stems from three main systemic conflicts: (or Virtual USB MultiKey )
Navigate to > Advanced options > Startup Settings > Restart .
The "Mastercam Virtual USB Bus Error" (often appearing as Error Code 39) generally stems from Windows blocking unverified or unsigned virtual drivers, particularly after system updates like KB5004237
Disable your antivirus software. Also, uninstall or disable any anti-cheat software like Riot Vanguard. For games like Valorant or League of Legends, you may need to uninstall the anti-cheat system and restart your computer.
Use the official Mastercam Support utility to generate a diagnostic report for technical support.