Error in SOAP receiver channel in Synchronous Proxy to SOAP scenario

Hi all,

We are experiencing an issue with a synchronous Proxy to SOAP scenario. Getting below error message in the SOAP receiver communication channel for the response message.

SOAP: Response message contains an errorXIAdapter/HTTP/ADAPTER.HTTP_EXCEPTION - HTTP 500 Internal Server Error

Returning to application. Exception: com.sap.engine.interfaces.messaging.api.exception.MessagingException: Error encountered while executing mapping: com.sap.aii.af.service.mapping.MappingException: com.sap.aii.utilxi.misc.api.ResourceException: Could not determine mapping steps for message 1364b76e-ecbf-11e4-85f4-000023acfde6.

We are running PI 7.4.

Any help is appreciated.

Thanks,

Pushpa