1. Check the sales order type : SPRO -- > Salse and distribution -- > Sales -- > Sales Documents -- > Sales document Header -- > Define sales document types
2. configuration of Delivery block in SPRO: SPRO --> LE -- > Shipping -- > Deliveries -- > Define reasons for Blocking in Shipping (Deliveries:Blocking Reasons/Criteria)
Sales order type (Delivery block reason/criteria configuration in SPRO)
原文：http://www.cnblogs.com/jefflu2012/p/4170052.html