Hi, The stack trace points out a legitimate bug. If the Drag starts, but then the mouse goes out of the app and the button is released without any mouseMove events coming into the DragProxy, the lastMouseEvent has not been set and you'll get this crash.
I'm not quite sure how you can get zero "mouseMove" events, but maybe if you drag fast enough while the app is computing the thing to drag. File a bug if you can. You shouldn't need to build the SDK to fix this problem. You can use monkey-patching instead. Search the internet for articles on "Flex Monkey Patching". Thanks, -Alex On 12/7/17, 1:13 PM, "Tucsonjhall" <jh...@cactusware.com> wrote: >I'm working with an s:Window component and using nativeDragAndDrop from >the >window to the main application. This works fine above 95% of the time but >then. Crash!!! > >TypeError: Error #1009: Cannot access a property or method of a null >object >reference. > at >mx.managers.dragClasses::DragProxy/mouseUpHandler()[/Users/justinmclean/Do >cuments/ApacheFlex4.16/frameworks/projects/framework/src/mx/managers/dragC >lasses/DragProxy.as:660] > at >mx.managers.dragClasses::DragProxy/mouseLeaveHandler()[/Users/justinmclean >/Documents/ApacheFlex4.16/frameworks/projects/framework/src/mx/managers/dr >agClasses/DragProxy.as:561] > at flash.events::EventDispatcher/dispatchEventFunction() > at flash.events::EventDispatcher/dispatchEvent() > at >mx.managers::WindowedSystemManager/mouseLeaveHandler()[/Users/justinmclean >/Documents/ApacheFlex4.16/frameworks/projects/airframework/src/mx/managers >/WindowedSystemManager.as:2306] > >I've been unable to stop the crash by wrapping anything in the main app >inside a try/catch. Does anyone have ideas about how I can prevent this? >Any >help would be greatly appreciated. My customers are getting pretty annoyed >when the app crashes > > > >-- >Sent from: >https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fapache-fle >x-users.2333346.n4.nabble.com%2F&data=02%7C01%7Caharui%40adobe.com%7Cbc48e >bcaad7246adb53908d53dc03f81%7Cfa7b1b5a7b34438794aed2c178decee1%7C0%7C0%7C6 >36482818266809201&sdata=0ujmOZoU3tZ%2FGMwe%2F6qQk2zCtG%2BZiIDP8mCyeIyQ4eo% >3D&reserved=0
