changeOrder is the application name (changeOrder.mxml) the error details is here:
ReferenceError: Error #1069: Property myCollection not found on changeOrder and there is no default value. at mx.binding.utils::ChangeWatcher/getHostPropertyValue()[E:\dev\3.0.x\frameworks\projects\framework\src\mx\binding\utils\ChangeWatcher.as:407] at mx.binding.utils::ChangeWatcher/getValue()[E:\dev\3.0.x\frameworks\projects\framework\src\mx\binding\utils\ChangeWatcher.as:332] at <anonymous>()[E:\dev\3.0.x\frameworks\projects\framework\src\mx\binding\utils\BindingUtils.as:144] at mx.binding.utils::BindingUtils$/bindSetter()[E:\dev\3.0.x\frameworks\projects\framework\src\mx\binding\utils\BindingUtils.as:147] at changeOrder/initApp()[C:\Documents and Settings\user\My Documents\Flex Builder 3\test0806\src\changeOrder.mxml:15] at changeOrder/___changeOrder_Application1_creationComplete()[C:\Documents and Settings\user\My Documents\Flex Builder 3\test0806\src\changeOrder.mxml:2] at flash.events::EventDispatcher/dispatchEventFunction() at flash.events::EventDispatcher/dispatchEvent() at mx.core::UIComponent/dispatchEvent()[E:\dev\3.0.x\frameworks\projects\framework\src\mx\core\UIComponent.as:9051] at mx.core::UIComponent/set initialized()[E:\dev\3.0.x\frameworks\projects\framework\src\mx\core\UIComponent.as:1167] at mx.managers::LayoutManager/doPhasedInstantiation()[E:\dev\3.0.x\frameworks\projects\framework\src\mx\managers\LayoutManager.as:698] at Function/http://adobe.com/AS3/2006/builtin::apply() at mx.core::UIComponent/callLaterDispatcher2()[E:\dev\3.0.x\frameworks\projects\framework\src\mx\core\UIComponent.as:8460] at mx.core::UIComponent/callLaterDispatcher()[E:\dev\3.0.x\frameworks\projects\framework\src\mx\core\UIComponent.as:8403]