TypeError: Error #1009: Cannot access a property or method of a null object reference

[ShaningYu]

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.

[RobertScheitlin__GISP · Accepted solution]

Shaning,

   Hmm... Still posting to the wrong forum.... This is a question about a Flex Viewer Widget.

http://forums.arcgis.com/forums/111-ArcGIS-Viewer-for-Flex

[ShaningYu]

Thanks.  Re-post at http://forums.arcgis.com/threads/61116-Error-1009-Cannot-access-a-property-or-method-of-a-null-objec...