Object reference not set to an instance of an object.

[johnsimons]

Using v1.2.6

System.NullReferenceException was unhandled
  HResult=-2147467261
  Message=Object reference not set to an instance of an object.
  Source=ServiceInsight
  StackTrace:
       at Particular.ServiceInsight.Desktop.MessageFlow.MessageFlowViewModel.OnShowMessage(Object sender, SearchMessageEventArgs e) in c:\Projects\ServiceInsight\src\ServiceInsight\MessageFlow\MessageFlowViewModel.cs:line 92
       at System.EventHandler`1.Invoke(Object sender, TEventArgs e)
       at Particular.ServiceInsight.Desktop.MessageFlow.MessageFlowView.MessageRectangle_MouseLeftButtonDown(Object sender, MouseButtonEventArgs e) in c:\Projects\ServiceInsight\src\ServiceInsight\MessageFlow\MessageFlowView.xaml.cs:line 51
       at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
       at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
       at System.Windows.UIElement.ReRaiseEventAs(DependencyObject sender, RoutedEventArgs args, RoutedEvent newEvent)
       at System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
       at System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
       at System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
       at System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
       at System.Windows.Input.InputManager.ProcessStagingArea()
       at System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport)
       at System.Windows.Interop.HwndMouseInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawMouseActions actions, Int32 x, Int32 y, Int32 wheel)
       at System.Windows.Interop.HwndMouseInputProvider.FilterMessage(IntPtr hwnd, WindowMessage msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
       at System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
       at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
       at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
       at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
       at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
       at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
       at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
       at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
       at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
       at System.Windows.Application.RunInternal(Window window)
       at System.Windows.Application.Run()
       at Particular.ServiceInsight.Desktop.App.Main() in c:\Projects\ServiceInsight\src\ServiceInsight\obj\Debug\App.g.cs:line 0
  InnerException: 

To replicate:

1. Right click on headers
   
2. Click on endpoint name in flowdiagram