If you are a legitimate user managing a shop floor, dealing with a "Multi-Key" involves configuring your and ensuring your Server is accessible to all client PCs. If you are attempting to update a license, you typically need to contact your Mastercam Reseller to receive the updated authorization code or license file.
Windows Update disabled unsigned drivers. Fix:
To help you put together a paper or documentation regarding "Multikey for Mastercam updates," it is important to first understand the context. MultiKey is a virtual USB emulator
Mastercam, developed by CNC Software, utilizes security systems (historically Hasp/Sentinel keys) to enforce licensing.