There's an issue some people are having where including a TabNavigator in a Module causes a nasty error. A thread on Adobe's forums can be found here:
http://www.adobe.com/cfusion/webforums/forum/messageview.cfm?forumid=60&catid=585&threadid=1236404&highlight_key=y&keyword1=module In essence, loading the module with the TabNavigator can cause this error: TypeError: Error #1009: Cannot access a property or method of a null object reference. at mx.managers::HistoryManager$/unregister()[C:\dev\flex_201_gmc\sdk\frameworks\mx\managers\HistoryManager.as:127] at mx.containers::ViewStack/mx.containers:ViewStack::commitProperties()[C:\dev\flex_201_gmc\sdk\frameworks\mx\containers\ViewStack.as:622] at mx.containers::TabNavigator/mx.containers:TabNavigator::commitProperties()[C:\dev\flex_201_gmc\sdk\frameworks\mx\containers\TabNavigator.as:386] at mx.core::UIComponent/validateProperties()[C:\dev\flex_201_gmc\sdk\frameworks\mx\core\UIComponent.as:5300] at mx.managers::LayoutManager/mx.managers:LayoutManager::validateProperties()[C:\dev\flex_201_gmc\sdk\frameworks\mx\managers\LayoutManager.as:517] at mx.managers::LayoutManager/mx.managers:LayoutManager::doPhasedInstantiation()[C:\dev\flex_201_gmc\sdk\frameworks\mx\managers\LayoutManager.as:637] at Function/http://adobe.com/AS3/2006/builtin::apply() at mx.core::UIComponent/mx.core:UIComponent::callLaterDispatcher2()[C:\dev\flex_201_gmc\sdk\frameworks\mx\core\UIComponent.as:7909] at mx.core::UIComponent/mx.core:UIComponent::callLaterDispatcher()[C:\dev\flex_201_gmc\sdk\frameworks\mx\core\UIComponent.as:7852] Has anyone experienced this and solved it?
