How to Fix Mastercam "Virtual USB Bus Error" (Code 39) in Windows 10 & 11 If you are running Mastercam X7 or even the more recent Mastercam 2022

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\36FC9E60-C465-11CF-8056-444553540000 Right-click and UpperFilters LowerFilters Restart your system. Reinstall MultiKey Drivers