Unpermitted combination of business object BUS2032 and sales doc. category H

Hi,

I am creating sales order with reference document type and i am using extensions also using bapi   BAPI_SALESORDER_CREATEFROMDAT2 ,

while executing BAPI i am getting the below error.

even though i passed field VGTYP = "H'.

Unpermitted combination of business object BUS2032 and sales doc. category H

Can any one help me how to resolve this error and create sales order with bapi.

Thanks & regards

kiran.