To refresh the Mastercam Configuration file, first make sure Mastercam shut down, then go into the Local Disk C drive, to Users, to your login, and to your documents to locate the "My Mcam" folder you need to reset.

Rename the "My Mcam2018" folder, or the "My Mcam" folder for whatever version you need to reset, we recommend adding "-old" or "-org" 

The next time Mastercam is turned on, it will regenerate the folder and Mastercam will be like a fresh install.