Proxy message failure

The Scenario is Ecc --> PI --> CRM system.Asynchronous message is hitting to PI system from ECC through proxy and processing to CRM .
 

Here the issue is Messages are failing in ECC itself with the mentioned error  "Attribute processing mode has the unexpected value "s" "a" was expected in sap ecc".

We are processing data in Async mode but it is popping out the error regarding Sync. Kindly do needful by providing the navigation to trace out the root cause.