Please see the attached article about "Z Calibration Error" 


Before printing the error messages that come up are of the following:

  1. "Please recalibrate z-axis"
  2. "Incorrect z-height"

Then the platform will continue to move upwards after touching with the nozzle during manual adjustment. The printer's sensor of z-axis calibration may have malfunctioned. Could also be caused by the sensitivity setting of the printer being too high/strong.