In the right pane, look for entries named and LowerFilters . Right-click and Delete both (if they exist). Restart your PC . Alternative Troubleshooting Mastercam X7-2022 Virtual Usb Bus Error 39 - Google Groups
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 This issue may arise due to a corrupted driver, outdated software, or a conflict with other system applications.
This distinction is crucial. Your driver files aren't necessarily corrupted or missing—they're being actively blocked by Windows because their digital signature is no longer trusted by the operating system. This is largely a result of Microsoft's ongoing security hardening, particularly affecting the virtual USB emulation drivers that older Mastercam versions rely on for license verification. The error has become increasingly common starting with Windows 10 version 20H1 and Windows 11, where Driver Signature Enforcement (DSE) and Secure Boot are enabled by default.
Once complete, install the new driver by running: haspdinst.exe -i . 4. Delete Corrupted Registry Filters mastercam x72022 virtual usb bus error 39 fix
Select .
In Device Manager, find the device with the yellow exclamation mark (Error 39), right-click, and select Uninstall device .
Simply reinstalling Mastercam or its drivers often fails because remnants of previous driver installations remain in the system. These leftover files can conflict with new installations, causing persistent Code 39 errors even after multiple reinstall attempts. In the right pane, look for entries named and LowerFilters
Check the box that says and click Uninstall . Clean the Registry Press Windows Key + R , type regedit , and press Enter .
Navigate to the following directory path: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\
In many cases, the specific error reads: *"The signing certificate for this file has been revoked". This means the certificate used to sign the virtual USB driver has been added to Microsoft's revocation list, making the driver untrustworthy in the eyes of Windows. click Restart now .
The is a driver signature and registry corruption issue, not a hardware failure. In 90% of cases, Fix 2 (Manual Reinstall) combined with Fix 3 (Registry Cleanup) resolves the error within 15 minutes.
The most common cause is Microsoft's enhanced driver verification. After certain Windows updates—such as KB5004237 for Windows 10—the system began blocking unverified device drivers altogether. Virtual USB multikey drivers that previously worked stopped functioning because Windows refused to load them without proper digital signatures.
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 .
If the driver is unsigned (common with emulators), Windows might block it during boot. Go to > Update & Security > Recovery . Under Advanced startup , click Restart now .