: Recent updates (specifically to Microsoft Visual C++ files like ) have been known to break older Mastercam virtual keys. Corrupt User Profiles
Provide the path to the driver file (typically C:\Windows\System32\drivers\multikey.sys ). mastercam virtual usb multikey not working
If the driver appears "working" in Device Manager but Mastercam still doesn't launch: Virtual Usb Multikey Mastercam Windows 10 - Google Groups : Recent updates (specifically to Microsoft Visual C++
