SAP Message PT033 - Object type & cannot be archived with the document class "ALF"

Diagnosis There is no valid document type assigned to the document class"ALF", for the object types you have chosen. For this reason, thesystem could not archive any lists of this object type, since theymust have the document class "ALF". Procedure Either choose different object types, or assign these object types toan appropriate document type in Customizing.