Legal control in deliveries created with reference to PO

Dear Experts,

How can we ensure legal control in deliveries created with reference to PO?

In material master, the legal control is maintained for material (MM02 / Foreign trade export tab / legal control). And therefore, when business user is doing return delivery (with movt type 161) then, system is giving error message as "The system carried out legal check. The result was negative" We are unable to perform GI for delivery because of this error message.

Thanks.