Diagnosis
You cannot copy the material assignment. Possible reasons:

• You tried to copy the assignment within the same category. Real multiple
assignment is only allowed when you copy the material to a differentcategory - that is, the existing and copied material assignments have tohave different categories.

• The material you want to copy is already assigned to a node within the
category of the new parent node. An article assignment always has to beunique within a category.

Procedure
Select a parent node that belongs to a category and to which thematerial you want to copy has not been assigned yet.