Answer to: Calibration Failure! error mssg on Z & XYZ calibrationThanks @jimmyglee for giving me hope. I had repeated XYZ calibration failures after installing the MK2.5 upgrade, despite the MK2S that I was upgrading having no problems. I tried a few things including lowering the PINDA to slightly less than cable tie-thickness distance from the nozzle tip but nothing helped. After reading about Jimmy's success above I tried cancelling the Wizard, and running "Calibrate Z axis" followed by "Mesh Bed Levelling", and following that I re-ran XYZ calibration and it worked! Wahoo! Pe Perhaps the printer is slightly too skewed for the default tolerances to cope with, and either the Z or Mesh Bed calibrations set some corrections in the firmware to allow XYZ to run without error. Perhaps not, but it works now!