Probably no reply because no one knows what to tell you. A following error means that it cannot keep up with the command of where the control expects the Z axis to be.
You could turn the feedrate override ON and lower the rapid rate to see what is going on. When moving slower see where it faults. Possible that the BMDCPRMS.sys file is corrupted. The Z axis rapid is slower than the X and Y.
The motors and drives are Siemens AC type so there are no brushes. The Z also has a brake built in and a special encoder.
Start there.
George
(Note: The opinions expressed in this post are my own and are not necessarily those of CNCzone and its management)