I’m having the same problem. I have the spindle, but it is the same error with the same message. I have queried the console and it shows PN:P status, indicating the probe is sensing a complete circuit. It also pulls up the green checkmark on the continuity check as soon as I press the probe button. It is doing this with the probe plugged into the controller or not- so I am thinking an internal problem in the controller? Edit: A 4x4 Altmill, everything set up according to web page, all components powered on and off repeatedly, “Invert probe inputs” toggled on and off- no change.