SAP Message WM519 - Assortment check only possible if no more than one distr.chain assigned

Diagnosis
You attempted to start a complete check of the assortments withoutfirst changing assortment control parameters (such as assortment gradeor listing procedure, for example). There are already severaldistribution chains maintained for the material.
It is only possible to call a complete check, however, if at least oneof the following applies: only one distribution chain is maintained oryou have changed listing parameters for a selected distribution chain.
There are plans to extend the functionality so that a new check can be
called here for any distribution chain.

System Response
Once assortments have been deleted and this change has been saved, theycannot be listed again using this function.

Procedure
Change an assortment control parameter or change the individual listingfor the distribution chain in the "Assortment" menu.