GridControl "Printing options" demo crashes when the window size decreases and then is maximized when the export menu is opened

Hello Support,

by using the standard print and export preview dialog we are getting an System.NullReferenceException (Object reference not set to an instance of an object).

C#
DevExpress.Xpf.Core.v15.1: System.NullReferenceException: Der Objektverweis wurde nicht auf eine Objektinstanz festgelegt.  

bei DevExpress.Xpf.Bars.BarSplitButtonItemLinkControl.OnMouseMove(MouseEventArgs e)  
bei System.Windows.UIElement.OnMouseMoveThunk(Object sender, MouseEventArgs e)  
bei System.Windows.Input.MouseEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)  
bei System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)  
bei System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)  
bei System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)  
bei System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)  
bei System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)  
bei System.Windows.UIElement.RaiseEvent(RoutedEventArgs args, Boolean trusted)  
bei System.Windows.Input.InputManager.ProcessStagingArea()  
bei System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)  
bei System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport)  
bei System.Windows.Interop.HwndMouseInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawMouseActions actions, Int32 x, Int32 y, Int32 wheel)  
bei System.Windows.Interop.HwndMouseInputProvider.FilterMessage(IntPtr hwnd, WindowMessage msg, IntPtr wParam, IntPtr lParam, Boolean& handled)  
bei System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)  
bei MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)  
bei MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)  
bei System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)  
bei MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)  

To reproduce the problem, you must to do the following:

1- Open the print preview dialog in a new window.
2- Make the window smaller so that the export button is no longer visible.
3- Open the dropdown popup and move the mouse over the export button.
4- Make the window bigger again and try to export as pdf file.
5- System.NullReferenceException is thrown.

To demonstrate the problem i have attached a simple demo…

Thanks with regards
Ali