Diagnosis
It is not possible to set the deletion flag. Possible reasons:

• The validity period of the assignment to change must lie within the
validity period of the parent node assignment. The valid-to date of thechild node assignment is greater than the new valid-to date of the nodeassignment to change.

• You want to set a deletion flag for an assignment that lies in the
future. The valid-from date must not be greater than the valid-to dateof the assignment to change.