NullReferenceException on click

[Manuel]

Hi guys, our centralized log management system reported the following unhandled exception on a customer's PC.

It seems something related to the OnMouseLeftButtonUp event on RadToggleButton control, but I'm not able to reproduce it on my machine.

Maybe you can help me?

The machine is running Windows 7 SP1 32-bit (Microsoft Windows NT 6.1.7601 Service Pack 1).

Here is the full stack trace of the error: 

System.NullReferenceException: La reference d'objet n'est pas definie e une instance d'un objet.
 Telerik.Windows.Controls.Docking.PaneGroupBase.ShowContextMenu(PaneGroupBase paneGroup, ExecutedRoutedEventArgs e)
 Telerik.Windows.Controls.Docking.PaneGroupBase.OnContextMenuCommandInvoke(Object sender, ExecutedRoutedEventArgs e)
 System.Windows.Input.CommandBinding.OnExecuted(Object sender, ExecutedRoutedEventArgs e)
 System.Windows.Input.CommandManager.ExecuteCommandBinding(Object sender, ExecutedRoutedEventArgs e, CommandBinding commandBinding)
 System.Windows.Input.CommandManager.FindCommandBinding(CommandBindingCollection commandBindings, Object sender, RoutedEventArgs e, ICommand command, Boolean execute)
 System.Windows.Input.CommandManager.FindCommandBinding(Object sender, RoutedEventArgs e, ICommand command, Boolean execute)
 System.Windows.Input.CommandManager.OnExecuted(Object sender, ExecutedRoutedEventArgs e)
 System.Windows.UIElement.OnExecutedThunk(Object sender, ExecutedRoutedEventArgs e)
 System.Windows.Input.ExecutedRoutedEventArgs.InvokeEventHandler(Delegate genericHandler, Object target)
 System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
 System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
 System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
 System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
 System.Windows.UIElement.RaiseEvent(RoutedEventArgs args, Boolean trusted)
 System.Windows.Input.RoutedCommand.ExecuteImpl(Object parameter, IInputElement target, Boolean userInitiated)
 System.Windows.Input.RoutedCommand.ExecuteCore(Object parameter, IInputElement target, Boolean userInitiated)
 MS.Internal.Commands.CommandHelpers.CriticalExecuteCommandSource(ICommandSource commandSource, Boolean userInitiated)
 System.Windows.Controls.Primitives.ButtonBase.OnClick()
 Telerik.Windows.Controls.RadToggleButton.OnClick()
 System.Windows.Controls.Primitives.ButtonBase.OnMouseLeftButtonUp(MouseButtonEventArgs e)
 Telerik.Windows.Controls.RadToggleButton.OnMouseLeftButtonUp(MouseButtonEventArgs e)
 System.Windows.UIElement.OnMouseLeftButtonUpThunk(Object sender, MouseButtonEventArgs e)
 System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
 System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
 System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
 System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
 System.Windows.UIElement.ReRaiseEventAs(DependencyObject sender, RoutedEventArgs args, RoutedEvent newEvent)
 System.Windows.UIElement.OnMouseUpThunk(Object sender, MouseButtonEventArgs e)
 System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
 System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
 System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
 System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
 System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
 System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
 System.Windows.UIElement.RaiseEvent(RoutedEventArgs args, Boolean trusted)
 System.Windows.Input.InputManager.ProcessStagingArea()
 System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
 System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport)
 System.Windows.Interop.HwndMouseInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawMouseActions actions, Int32 x, Int32 y, Int32 wheel)
 System.Windows.Interop.HwndMouseInputProvider.FilterMessage(IntPtr hwnd, WindowMessage msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
 System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
 MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
 MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
 System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
 MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler).

[Geri]

Hi Manuel,

The error usually occurs when there is no pane selected. Therefore, a ContextMenu can not be opened and an exception is thrown.
By design, every RadPaneGroup always has a selected pane, so you can check if there is a specific logic that interferes with the selection.

Attached you can find a sample project where this behavior can be observed, we hope you'll find it helpful.

Regards,
Geri
Telerik