Kitagawa 4th axis/Mitsubishi controller issues-please help

I'm an engineering manager. We have a new machinist who is attempting to use our Kitagawa Tech Mara 4th axis on the mill. The controller is Mitsubishi. The controller recognizes the 4th axis, but will not allow us to operate it. We keep getting M01 internal interlock axis error code. We have used it before on this machine many years ago, but the machinist who was operating the machine at the time is no longer employed here. I know there is an activation code in the settings somewhere, but don't remember how to access it. Any help would be appreciated.

thanks.