The burrs are blocked by foreign matter.
Follow the guide below for detailed instructions:
If necessary, using a vacuum cleaner to remove any remaining beans.
Lining it up with 'INSERT'.
Then turn it to the right as far as it will go.
Grinding begins when the filter holder reaches the 'CLOSE' position and stops automatically.
Release the beans container by turning it anticlockwise and extract from the appliance.
Also, remove the coffee residues using a vacuum cleaner.
If it is correctly inserted, it will not move.