Syndication error from XI to R3

We are getting a IDOC error with status 51 when we are syndicating changes from XI to SAP R3. The error is - The function module IDOC_INPUT_DEBITOR_MDM, which was called for the application input, was not able to process the IDoc. A possible cause is that the IDoc has wrong message type or IDoc type.

We have configured the basic type of IDOC to DEBMDM05 & message type to DEBMDM.

Can anyone suggest corrective actions.