Hello. I have the some problem with setting background image.
I have the class based on ShapeNode. Contrctuctor is the following

        public TPDESwitchNode():base()
        {
            HandlesStyle = HandlesStyle.Custom;
            SetBackgroundImg();
            Type = NodeType.Switch;
        }
        private void SetBackgroundImg()
        {
            BitmapImage bi = new BitmapImage();
            bi.BeginInit();
            bi.UriSource = new Uri("pack://application:,,,/Images/Nodes/switch.png");
            bi.EndInit();
            Image = bi;
        }
 

And when I drop this node on the diagram by mouse (in the NodeCreated remove the NodeAdapter and create the object of the TPDESwitchNode class) after NodeActivated I see the following exception:
A first chance exception of type 'System.NotSupportedException' occurred in PresentationCore.dll
If I comment SetBackgroundImg() all works nice. Can you help me?

It is not unhandled exception. It means that I don't catch it into DispatcherUnhandledException handler of the App, but in the same time my another code also doesn't this exception. It is oocurs after I call Diagram.SaveToString method. In my project I need to save copy of the diagram as compressed xml into Hashtable.
Call stack:

>      Technologist.exe!Technologist.Utils.SaveDiagram(MindFusion.Diagramming.Wpf.Diagr
am a_Diagram) Line 222      C#
     Technologist.exe!Technologist.App.UpdateDiagramIntoHashTable(MindFusion.Diagramm
ing.Wpf.Diagram a_Diagram, int a_nDiagramId) Line 395 + 0x8 bytes      C#
     Technologist.exe!Technologist.TPDEDiagram.OnDiagram_Drop(object sender, System.Windows.DragEventArgs e) Line 250 + 0x11 bytes      C#
     PresentationCore.dll!System.Windows.DragEventArgs.InvokeEventHandler(System.Dele
gate genericHandler, object genericTarget) + 0x31 bytes      
     PresentationCore.dll!System.Windows.RoutedEventArgs.InvokeHandler(System.Delegat
e handler, object target) + 0x36 bytes      
     PresentationCore.dll!System.Windows.RoutedEventHandlerInfo.InvokeHandler(object target, System.Windows.RoutedEventArgs routedEventArgs) + 0x40 bytes      
     PresentationCore.dll!System.Windows.EventRoute.InvokeHandlersImpl(object source, System.Windows.RoutedEventArgs args, bool reRaised) + 0x1ae bytes      
     PresentationCore.dll!System.Windows.UIElement.RaiseEventImpl(System.Windows.Depe
ndencyObject sender, System.Windows.RoutedEventArgs args) + 0x79 bytes      
     PresentationCore.dll!System.Windows.UIElement.RaiseEvent(System.Windows.RoutedEv
entArgs e) + 0x29 bytes      
     PresentationCore.dll!System.Windows.OleDropTarget.RaiseDragEvent(System.Windows.
RoutedEvent dragEvent, int dragDropKeyStates, ref int effects, System.Windows.DependencyObject target, System.Windows.Point targetPoint) + 0x210 bytes      
     PresentationCore.dll!System.Windows.OleDropTarget.MS.Win32.UnsafeNativeMethods.I
OleDropTarget.OleDrop(object data, int dragDropKeyStates, long point, ref int effects) + 0x91 bytes      
     [Native to Managed Transition]      
     [Managed to Native Transition]      
     PresentationCore.dll!System.Windows.OleServicesContext.OleDoDragDrop(System.Runt
ime.InteropServices.ComTypes.IDataObject dataObject, MS.Win32.UnsafeNativeMethods.IOleDropSource dropSource, int allowedEffects, int[] finalEffect) + 0x7a bytes      
     PresentationCore.dll!System.Windows.DragDrop.OleDoDragDrop(System.Windows.Depend
encyObject dragSource, System.Windows.DataObject dataObject, System.Windows.DragDropEffects allowedEffects) + 0x48 bytes      
     PresentationCore.dll!System.Windows.DragDrop.DoDragDrop(System.Windows.Dependenc
yObject dragSource, object data, System.Windows.DragDropEffects allowedEffects) + 0x52 bytes      
     MindFusion.Diagramming.Wpf.dll!MindFusion.Diagramming.Wpf.NodeListView.OnPreview
MouseMove(System.Windows.Input.MouseEventArgs e) + 0x33e bytes      
     PresentationCore.dll!System.Windows.UIElement.OnPreviewMouseMoveThunk(object sender, System.Windows.Input.MouseEventArgs e) + 0x59 bytes      
     PresentationCore.dll!System.Windows.Input.MouseEventArgs.InvokeEventHandler(Syst
em.Delegate genericHandler, object genericTarget) + 0x34 bytes      
     PresentationCore.dll!System.Windows.RoutedEventArgs.InvokeHandler(System.Delegat
e handler, object target) + 0x36 bytes      
     PresentationCore.dll!System.Windows.RoutedEventHandlerInfo.InvokeHandler(object target, System.Windows.RoutedEventArgs routedEventArgs) + 0x40 bytes      
     PresentationCore.dll!System.Windows.EventRoute.InvokeHandlersImpl(object source, System.Windows.RoutedEventArgs args, bool reRaised) + 0x133 bytes      
     PresentationCore.dll!System.Windows.UIElement.RaiseEventImpl(System.Windows.Depe
ndencyObject sender, System.Windows.RoutedEventArgs args) + 0x79 bytes      
     PresentationCore.dll!System.Windows.UIElement.RaiseTrustedEvent(System.Windows.R
outedEventArgs args) + 0x41 bytes      
     PresentationCore.dll!System.Windows.UIElement.RaiseEvent(System.Windows.RoutedEv
entArgs args, bool trusted) + 0x42 bytes      
     PresentationCore.dll!System.Windows.Input.InputManager.ProcessStagingArea() + 0x1ff bytes      
     PresentationCore.dll!System.Windows.Input.InputManager.ProcessInput(System.Windo
ws.Input.InputEventArgs input) + 0x45 bytes      
     PresentationCore.dll!System.Windows.Input.InputProviderSite.ReportInput(System.W
indows.Input.InputReport inputReport) + 0x62 bytes      
     PresentationCore.dll!System.Windows.Interop.HwndMouseInputProvider.ReportInput(S
ystem.IntPtr hwnd, System.Windows.Input.InputMode mode, int timestamp, System.Windows.Input.RawMouseActions actions, int x, int y, int wheel) + 0x263 bytes      
     PresentationCore.dll!System.Windows.Interop.HwndMouseInputProvider.FilterMessage
(System.IntPtr hwnd, MS.Internal.Interop.WindowMessage msg, System.IntPtr wParam, System.IntPtr lParam, ref bool handled) + 0x198 bytes      
     PresentationCore.dll!System.Windows.Interop.HwndSource.InputFilterMessage(System
.IntPtr hwnd, int msg, System.IntPtr wParam, System.IntPtr lParam, ref bool handled) + 0x75 bytes      
     WindowsBase.dll!MS.Win32.HwndWrapper.WndProc(System.IntPtr hwnd, int msg, System.IntPtr wParam, System.IntPtr lParam, ref bool handled) + 0xbe bytes      
     WindowsBase.dll!MS.Win32.HwndSubclass.DispatcherCallbackOperation(object o) + 0x7d bytes      
     WindowsBase.dll!System.Windows.Threading.ExceptionWrapper.InternalRealCall(Syste
m.Delegate callback, object args, int numArgs) + 0x53 bytes      
     WindowsBase.dll!MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(object source, System.Delegate method, object args, int numArgs, System.Delegate catchHandler) + 0x42 bytes      
     WindowsBase.dll!System.Windows.Threading.Dispatcher.InvokeImpl(System.Windows.Th
reading.DispatcherPriority priority, System.TimeSpan timeout, System.Delegate method, object args, int numArgs) + 0xb4 bytes      
     WindowsBase.dll!MS.Win32.HwndSubclass.SubclassWndProc(System.IntPtr hwnd, int msg, System.IntPtr wParam, System.IntPtr lParam) + 0x104 bytes      
     [Native to Managed Transition]      
     [Managed to Native Transition]      
     WindowsBase.dll!System.Windows.Threading.Dispatcher.PushFrameImpl(System.Windows
.Threading.DispatcherFrame frame) + 0xc1 bytes      
     WindowsBase.dll!System.Windows.Threading.Dispatcher.PushFrame(System.Windows.Thr
eading.DispatcherFrame frame) + 0x49 bytes      
     WindowsBase.dll!System.Windows.Threading.Dispatcher.Run() + 0x4c bytes      
     PresentationFramework.dll!System.Windows.Application.RunDispatcher(object ignore) + 0x17 bytes      
     PresentationFramework.dll!System.Windows.Application.RunInternal(System.Windows.
Window window) + 0x6f bytes      
     PresentationFramework.dll!System.Windows.Application.Run(System.Windows.Window window) + 0x26 bytes      
     PresentationFramework.dll!System.Windows.Application.Run() + 0x1b bytes      
     Technologist.exe!Technologist.App.Main() + 0x5e bytes      C#
     [Native to Managed Transition]      
     [Managed to Native Transition]      
     mscorlib.dll!System.AppDomain.ExecuteAssembly(string assemblyFile, System.Security.Policy.Evidence assemblySecurity, string[] args) + 0x6d bytes      
     Microsoft.VisualStudio.HostingProcess.Utilities.dll!Microsoft.VisualStudio.Hosti
ngProcess.HostProc.RunUsersAssembly() + 0x2a bytes      
     mscorlib.dll!System.Threading.ThreadHelper.ThreadStart_Context(object state) + 0x63 bytes      
     mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionCon
text executionContext, System.Threading.ContextCallback callback, object state, bool ignoreSyncCtx) + 0xb0 bytes      
     mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionCon
text executionContext, System.Threading.ContextCallback callback, object state) + 0x2c bytes      
     mscorlib.dll!System.Threading.ThreadHelper.ThreadStart() + 0x44 bytes      
     [Native to Managed Transition]      

Te image is showing. But message litter the output console

OK Thanks