SAP Message 29792 - No plant has been assigned to sales order item & &

Diagnosis
You want to create, change or display an order BOM. However, in salesorder &V1& no plant was entered in item &V2&.

System Response
The system cannot create, change or display the order BOM.

Procedure
Choose Logistics -> Sales and distribution -> Sales.
The Sales screen appears.
Choose Order -> Change.
The Change Sales Order: Initial Screen appears.
Enter order number &V1& and choose Item overview.
The sales order item overview screen appears.
Enter a plant for item &V2& and save the sales document.