Repeated crashes when multiple Mastercam instances are open can corrupt a Windows User Profile, leading to Virtual USB Bus errors. Deleting and recreating the user profile is a known fix for persistent launch failures. Google Groups Installation and Troubleshooting
: On Windows 10/11, "Memory Integrity" (under Windows Security > Device Security > Core Isolation) often blocks these drivers. This must be toggled Off for the virtual bus to load. mastercam x7-2022 virtual usb bus driver