I loaded a component to export map to PDF (async one) from http://www.arcgis.com/home/item.html?id=a6dddf4d4297436c8af697d9965f1dd7. However, I got a runtime error: TypeError: Error #1009: Cannot access a property or method of a null object reference at WidgetManager.mxml's Line 403, widget.widgetId = widgetId; // Its value = 8 as traced when I clicked the tool's icon to open the widget. What's the possible reason for the failure? I will appreciate if someone can hint me how to debug this problem. Thanks.