Hey everyone, I've been hunting a bug down for a while now in a Flex project:
*This is the generated error:* TypeError: Error #1009: Cannot access a property or method of a null object reference. *at mx.controls.listClasses::ListBase/collectionChangeHandler()** [C:\dev\flex_201_gmc\sdk\frameworks\mx\controls\listClasses\ListBase.as:6496] * at mx.controls.listClasses::TileBase/collectionChangeHandler ()[C:\dev\flex_201_gmc\sdk\frameworks\mx\controls\listClasses\TileBase.as:1981] at flash.events::EventDispatcher/dispatchEventFunction() at flash.events::EventDispatcher/dispatchEvent() at mx.collections::ListCollectionView/dispatchEvent ()[C:\dev\flex_201_gmc\sdk\frameworks\mx\collections\ListCollectionView.as:833] at mx.collections::ListCollectionView/moveItemInView ()[C:\dev\flex_201_gmc\sdk\frameworks\mx\collections\ListCollectionView.as:1316] at mx.collections::ListCollectionView/handlePropertyChangeEvents ()[C:\dev\flex_201_gmc\sdk\frameworks\mx\collections\ListCollectionView.as:1124] at mx.collections::ListCollectionView/listChangeHandler ()[C:\dev\flex_201_gmc\sdk\frameworks\mx\collections\ListCollectionView.as:1042] at flash.events::EventDispatcher/dispatchEventFunction() at flash.events::EventDispatcher/dispatchEvent() at mx.collections::ArrayList/internalDispatchEvent ()[C:\dev\flex_201_gmc\sdk\frameworks\mx\collections\ArrayList.as:518] at mx.collections::ArrayList/itemUpdateHandler ()[C:\dev\flex_201_gmc\sdk\frameworks\mx\collections\ArrayList.as:544] at flash.events::EventDispatcher/dispatchEventFunction() at flash.events::EventDispatcher/dispatchEvent() *The rule that throws the error* // RULE 6493 in ListBase.as //( found at : C:\Program Files\Adobe\Flex Builder 2 Plug-in\Flex SDK 2\frameworks\source\mx\controls\listClasses ) // make sure we've generated rows for the actual data // at startup time we might just have blank rows if (listItems.length && listItems[lockedRowCount].length ) *Screenshot* For those interested, this is the dump of listItems: screenshot<http://content.screencast.com/media/d25bbc5a-9b36-42ee-8393-b2e2f48929f8_8373bf5e-323c-46b9-94a3-68ac1e9fbb8f_static_0_0_image.png> Any thought are greatly appreciated! Bram
