500 Internal Server Error while executing Gateway Service

I have created a project in SEGW for RFC.  When i execute this service it gives status as "500 Internal Server Error" .

Exception occurs when the following method is executed : /IWFND/IF_SODATA_MAPPER~GET_ENTITY_PROV_BY_FEED_DATA.

Also I noticed that if the queried table has some output data only then this Internal Server error occurs whereas the status is "200 OK" when there is no output data.

Please help me to solve this issue.