DataManager not created

I think this problem has something to do with linking or old files, but I've updated everything I can think of. I get a runtime error when trying to start an Ogre application. Log:

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loging report for : 04/23/2010 14:41:27
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14:41:27 | Core | Info | * Initialise: Gui | ..\..\MyGUIEngine\src\MyGUI_Gui.cpp | 77
14:41:27 | Core | Info | * MyGUI version 3.1.0 | ..\..\MyGUIEngine\src\MyGUI_Gui.cpp | 81
14:41:27 | Core | Info | * Initialise: ResourceManager | ..\..\MyGUIEngine\src\MyGUI_ResourceManager.cpp | 42
14:41:27 | Core | Info | ResourceManager successfully initialized | ..\..\MyGUIEngine\src\MyGUI_ResourceManager.cpp | 50
14:41:27 | Core | Info | * Initialise: LayerManager | ..\..\MyGUIEngine\src\MyGUI_LayerManager.cpp | 43
14:41:27 | Core | Info | LayerManager successfully initialized | ..\..\MyGUIEngine\src\MyGUI_LayerManager.cpp | 51
14:41:27 | Core | Info | * Initialise: WidgetManager | ..\..\MyGUIEngine\src\MyGUI_WidgetManager.cpp | 68
14:41:27 | Core | Info | WidgetManager successfully initialized | ..\..\MyGUIEngine\src\MyGUI_WidgetManager.cpp | 110
14:41:27 | Core | Info | * Initialise: InputManager | ..\..\MyGUIEngine\src\MyGUI_InputManager.cpp | 56
14:41:27 | Core | Info | InputManager successfully initialized | ..\..\MyGUIEngine\src\MyGUI_InputManager.cpp | 70
14:41:27 | Core | Info | * Initialise: SubWidgetManager | ..\..\MyGUIEngine\src\MyGUI_SubWidgetManager.cpp | 43
14:41:27 | Core | Info | SubWidgetManager successfully initialized | ..\..\MyGUIEngine\src\MyGUI_SubWidgetManager.cpp | 63
14:41:27 | Core | Info | * Initialise: SkinManager | ..\..\MyGUIEngine\src\MyGUI_SkinManager.cpp | 44
14:41:27 | Core | Info | SkinManager successfully initialized | ..\..\MyGUIEngine\src\MyGUI_SkinManager.cpp | 52
14:41:27 | Core | Info | * Initialise: FontManager | ..\..\MyGUIEngine\src\MyGUI_FontManager.cpp | 42
14:41:27 | Core | Info | FontManager successfully initialized | ..\..\MyGUIEngine\src\MyGUI_FontManager.cpp | 51
14:41:27 | Core | Info | * Initialise: ControllerManager | ..\..\MyGUIEngine\src\MyGUI_ControllerManager.cpp | 40
14:41:27 | Core | Info | ControllerManager successfully initialized | ..\..\MyGUIEngine\src\MyGUI_ControllerManager.cpp | 50
14:41:27 | Core | Info | * Initialise: PointerManager | ..\..\MyGUIEngine\src\MyGUI_PointerManager.cpp | 58
14:41:27 | Core | Info | PointerManager successfully initialized | ..\..\MyGUIEngine\src\MyGUI_PointerManager.cpp | 73
14:41:27 | Core | Info | * Initialise: ClipboardManager | ..\..\MyGUIEngine\src\MyGUI_ClipboardManager.cpp | 81
14:41:27 | Core | Info | ClipboardManager successfully initialized | ..\..\MyGUIEngine\src\MyGUI_ClipboardManager.cpp | 95
14:41:27 | Core | Info | * Initialise: LayoutManager | ..\..\MyGUIEngine\src\MyGUI_LayoutManager.cpp | 51
14:41:27 | Core | Info | LayoutManager successfully initialized | ..\..\MyGUIEngine\src\MyGUI_LayoutManager.cpp | 57
14:41:27 | Core | Info | * Initialise: DynLibManager | ..\..\MyGUIEngine\src\MyGUI_DynLibManager.cpp | 35
14:41:27 | Core | Info | DynLibManager successfully initialized | ..\..\MyGUIEngine\src\MyGUI_DynLibManager.cpp | 39
14:41:27 | Core | Info | * Initialise: PluginManager | ..\..\MyGUIEngine\src\MyGUI_PluginManager.cpp | 35
14:41:27 | Core | Info | PluginManager successfully initialized | ..\..\MyGUIEngine\src\MyGUI_PluginManager.cpp | 39
14:41:27 | Core | Info | * Initialise: LanguageManager | ..\..\MyGUIEngine\src\MyGUI_LanguageManager.cpp | 39
14:41:27 | Core | Info | LanguageManager successfully initialized | ..\..\MyGUIEngine\src\MyGUI_LanguageManager.cpp | 43
14:41:27 | Core | Info | * Initialise: FactoryManager | ..\..\MyGUIEngine\src\MyGUI_FactoryManager.cpp | 33
14:41:27 | Core | Info | FactoryManager successfully initialized | ..\..\MyGUIEngine\src\MyGUI_FactoryManager.cpp | 36
14:41:27 | Core | Info | * Initialise: ToolTipManager | ..\..\MyGUIEngine\src\MyGUI_ToolTipManager.cpp | 49
14:41:27 | Core | Info | ToolTipManager successfully initialized | ..\..\MyGUIEngine\src\MyGUI_ToolTipManager.cpp | 53
14:41:27 | Core | Critical | instance DataManager was not created | ..\..\MyGUIEngine\src\MyGUI_DataManager.cpp | 50


Why isn't DataManager being created?

You should create and initialise OgrePlatform.
http://www.ogre3d.org/wiki/index.php/MyGUI_quickstart
MyGUI::OgrePlatform* mPlatform = new MyGUI::OgrePlatform();
mPlatform->initialise(mWindow, mSceneManager); // mWindow is Ogre::RenderWindow*, mSceneManager is Ogre::SceneManager*
mGUI = new MyGUI::Gui();
mGUI->initialise();
Probably you don't have first two lines.