Free goods determination: Mandatory pricing condition 0PR0 Missing - Pricing error

hi guys,

i tried creating Free goods in my sales order.

i used the below combination of Item category detrmination..

ZNSH + St.item = ZNQT -> Sale order item detrmination

ZNSH + St.Item + Free goods + ZNQT = ZFGI - > Free goods determination

while creating sale order, free goods is determined for my product. but its throwing me an error as mentioned above..

How over i can save the sales order....

Can any one let me know how do i resolve this issue ....