Diagnosis
The "Valid to" date &V1& of the assignment lies after the "Valid to"date &V2& of the node to which you want to assign the material. However,you can only schedule an assignment until the end date of the nodevalidity period.

System Response
The system cannot copy the entered assignments.

Procedure
Adjust the "Valid to" date of the assignments in such a way that they donot lie after the &V2&.
The "Valid to" date was linked using the methodVALIDITY_CHECK_FOR_ARTICLE of the BAdI BADI_MATGRP_HIER_CHK
. In the standard system, this linkage is not activated and the checkerror will not be issued.