Java Exception during we click the item short description in search result

Hi Expert,

We are in SRM-MDM Catalog 3.0.

When we click a item's short description in catalog search result list to open the item detail, the new screen opened with a internal server error. And the error summary is "java.lang.NullPointerException: The relationship ID is not an optional parameter." I have validated the XML mapping, I can not find any fields which were used for the "relationship ID".