¶ What it is
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.
¶ What to do
¶ step1
Check if the nozzle is severely worn as below:
¶ step2
If the nozzle is OK, run "Calibration" to dismiss the warning message.
¶ How to verify completion/success
Restart the printer and start a print job. The message should disappear if problem solved.