HMS_0C00_0200_0002_0004: Nozzle too low
After using the printer for a long time, the nozzle may be worn, and its height is lower than the saved valued when the printer is produced.
Another case is, the toolhead crashes with printed objects or something, and the nozzle is tilted, then the detected nozzle height is also different from saved value.
Check if the nozzle is severely worn as below:
If the nozzle is OK, run "Calibration" to dismiss the warning message.
Restart the printer and start a print job. The message should disappear if problem solved.