SAP AII Error :Business Transaction Document xxx of type inbound delivery does not exist

Hi

I am sending an IDoc (DESADV-DLVRY05) when creating an inbound delivery from my SAP ECC system to PI and from PI to SAP -AII(message DespatchedDeliveryNotificationIn). but the proxy fails due to Error (Business Transaction Document xxx of type inbound delivery does not exist)

where xxx is my inbound delivery no from the ecc system.

Please can anyone let me how to solve the error message and where i am going wrong.

Thanks And Regads

Lalith