Hi Axel, Gruesse aus Bahrain (greetings from Bahrain)
You are getting this message because you don’t have automatic Z adjustment.
Without the Z-motor, GroundControl will stop each time the gcode has a change in Z-hight. You then have to adjust the depth of your router manually and then tell GC to continue.
So if your gcode has a line telling Z -3, GC stops and you manually lower the router 3 mm. Hope I could explain that in a way that it is understandable.
Is correct without the Z-motor.
Kind regards, Gero