DeliveryHeader failed

I am getting the below error

There was a failure executing the receive pipeline: "Microsoft.Solutions.BTARN.Pipelines.Receive,
 Microsoft.Solutions.BTARN.PipelineReceive, Version=3.3.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" 
Source: "RN Disassembler" Receive Port: "RNIF_Async_Receive" 
URI: "/BTARNHttpReceive/BTSHTTPReceive.dll?xRNResponseType=async" 
Reason: Finding the document specification by message type "DeliveryHeader" failed. Verify the schema deployed properly.

Please help how to get the XML that was sent  by the vendor and how to verify the delivery header

Regards Suresh