error: The value in the Weight …

hi,

i want an label for international sending to spain, i get this error:
Error creating label:
Error :
( customs.items[0] ) : The value in the Weight / Unit field must be in the format 0.000 kg and value must be greater than 0.
( customs.items[0] ) : The value in the Weight / Unit field must be in the format 0.000 kg and value must be greater than 0.

on “Weight” > Voraussichtlichtes Gewicht (kg) der Sendung auf Basis der bestellten Produkte:
i added “1”

please help