SAP Message VW637 - Partner maint.not possible; Customizing shpmnt type &1 does not have &2

Diagnosis
You have attempted to switch to the tabstrip control for partnermaintenance. The system requires a partner determination procedure forpartner maintenance, but the shipment type of the current shipment doesnot contain any.

Procedure
In Customizing (Define and assign partner determinationprocedure), assign a partner determination procedure to the shipmenttype.