The Supertech servo system was developed by Dennis Bohlke, and nobody else knows much about it. It works with his Supercam software, which is another one of his own proprietary products that isn't the same as the regular G-code everyone else uses. If you can't got it to work, you might try some basic troubleshooting, like pulling off the motors and running the screws by hand to see if there's some kind of mechanical problem that's triggering the servo faults, that normally should only happen if the mill-head hits an obstruction, or there's an issue with the screws or slides. Make sure all of those are well-lubricated and running smoothly.
If there are no mechanical issues, the problems persist, and Dennis remains unavailable to help you've got two choices: either replace the controller with one that has compatible servo drivers (you might look at the Gecko 320 drives, which work with any brushed servos), or replace the whole servo control system -motors and all - with a stepper-based system like everyone else uses on these machines. Taig's own system would work, or you could build your own, using the Gecko G540 (which is quite popular for these machines) or whatever other components.you can find,