An issue exists in SmartClient version 6.5.1 whereby in some cases hiding fields in a ListGrid which is currently showing editors could lead to a Javascript error similar to "autoCompleteCandidates is undefined".

This patch code should address this issue:
Code:
//----------------------------------------------------------------------------
// Isomorphic SmartClient 6.5.1 patch
// Purpose: Fix for a case where showing and hiding fields in an editable ListGrid
// could lead to JavaScript Errors in IE.
// 
// Applies to SmartClient 6.5.1 build only
//----------------------------------------------------------------------------
if (window.isc && isc.version.startsWith("6.5.1/") ){
if (isc.ListGrid) {
isc.ListGrid.addProperties({
    pgdf:isc.ListGrid.getPrototype().getDrawnFields,
    getDrawnFields:function () {
        var drawnFields = this.pgdf();
        drawnFields.removeEmpty();
        return drawnFields;
    }
});
}

});

} else if (window.isc) {
  isc.Log.logWarn("Patch for SmartClient 6.5.1 build included in this application. " +
            "You are currently running SmartClient verion '"+ isc.version + 
            "'. This patch is not compatible with this build and will have no effect. " +
            "It should be removed from your application source.");

}

// End of patch
// ------------