SharePoint external content types define both how to run an ECT-enabled mashup and information about the parameters for and results from that mashup. This is defined in a WSDL (web-service definition) when the external content type is created.

Because of this, changes to the parameters for an ECT-enabled mashup or the number, name or types of data for each field in its results affect the information in the mashup’s WSDL. Any of these change can cause the external content type to break and cause errors in the related external content lists in SharePoint.

To fix problems caused by changes to the results or parameters for an ECT-enabled mashup, you must delete and recreate the external content type and related external content lists for that mashup in SharePoint Designer.