E16 appears; machine cannot detect coffee beans or reports grinder empty even when full.

Safety: Unplug the machine before accessing the bean hopper.

• Stir beans: Gently stir the beans in the hopper to break up clumps, especially if using very oily dark roasts.
• Clean hopper and chute: Empty the hopper and vacuum out dust and fragments. Clean the chute leading to the grinder with a dry brush.
• Check sensor window: For optical sensors, clean the sensor window inside the hopper area with a soft cloth.
• Test with different beans: Try a fresh, less oily bean to see if detection improves. If not, inspect and replace the bean level sensor if accessible.