Why the unit indicates that I need to empty the trays, but they are already empty?

To avoid overspilling, the machine counts the number of espressos that are made, and prompts you to empty the drip tray.

If you empty the drip tray manually when the machine is off, then you may get a notification to empty it when it's not needed.

If this happens, just pull out the drip tray to reset the espresso counter. You can pull out the tray when the machine is on at any time to reset the counter.