public RadForm1()
        {
            InitializeComponent(); 
            System.Threading.Thread.CurrentThread.CurrentCulture = culture;
            System.Threading.Thread.CurrentThread.CurrentUICulture = culture;

            this.radChat1.Author = new Author(Properties.Resources.bot, "Nancy");

            Author author2 = new Author(Properties.Resources.bot, "Andrew");
            ChatTextMessage message1 = new ChatTextMessage("Hello", author2, DateTime.Now.AddHours(1));
            this.radChat1.AddMessage(message1);
            ChatTextMessage message2 = new ChatTextMessage("Hi", this.radChat1.Author, DateTime.Now.AddHours(1).AddMinutes(10));
            this.radChat1.AddMessage(message2);
            ChatTextMessage message3 = new ChatTextMessage("We would like to announce that in the R2 2018 release " +
                                                           "we introduced Conversational UI", author2, DateTime.Now.AddHours(3));
            this.radChat1.AddMessage(message3);
            ChatTextMessage message4 = new ChatTextMessage("This control provides rich conversational experience " +
                                                           "that goes beyond the natural language understanding and " +
                                                           "personality of your chatbot.", author2, DateTime.Now.AddHours(3));
            this.radChat1.AddMessage(message4);

            calendarOverlay = new ChatCalendarOverlay("Select a date");
            Author author = new Author(Properties.Resources.bot, "Andrew");
            ChatOverlayMessage overlayMessage = new ChatOverlayMessage(calendarOverlay, author, DateTime.Now);        
            this.radChat1.AddMessage(overlayMessage);
        }

System.IndexOutOfRangeException: Index was outside the bounds of the array.
   at Telerik.Windows.Documents.Spreadsheet.Layout.RadWorksheetLayout.GetColumnWidth(Int32 columnIndex)
   at Telerik.WinForms.Controls.Spreadsheet.Worksheets.RadWorksheetEditorPresenterBase.SetHorizontalOffsetInternal(ScrollEventType scrollType, Double value)
   at Telerik.WinForms.Controls.Spreadsheet.Worksheets.RadWorksheetEditor.SetHorizontalOffsetInternal(ScrollEventType scrollType, Double value)
   at Telerik.WinControls.UI.RadSpreadsheetElement.ScrollBar_Scroll(Object sender, ScrollEventArgs e)
   at System.Windows.Forms.ScrollEventHandler.Invoke(Object sender, ScrollEventArgs e)
   at Telerik.WinControls.UI.RadScrollBarElement.OnScroll(ScrollEventArgs args)
   at Telerik.WinControls.UI.RadScrollBarElement.CallOnScroll(ScrollEventType scrollType, Int32 oldValue, Int32 newValue)
   at Telerik.WinControls.UI.RadScrollBarElement.ScrollWith(Int32 step, ScrollEventType scrollType)
   at Telerik.WinControls.UI.RadScrollBarElement.OnScrollTimer(Object sender, EventArgs e)
   at Telerik.WinControls.UI.RadScrollBarElement.OnMouseDown(MouseEventArgs e)
   at Telerik.WinControls.RadElement.OnCLREventsRise(RoutedEventArgs args)
   at Telerik.WinControls.RadElement.OnBubbleEvent(RadElement sender, RoutedEventArgs args)
   at Telerik.WinControls.RadElement.RaiseBubbleEvent(RadElement sender, RoutedEventArgs args)
   at Telerik.WinControls.RadItem.RaiseBubbleEvent(RadElement sender, RoutedEventArgs args)
   at Telerik.WinControls.RadElement.RaiseBubbleEvent(RadElement sender, RoutedEventArgs args)
   at Telerik.WinControls.RadItem.RaiseBubbleEvent(RadElement sender, RoutedEventArgs args)
   at Telerik.WinControls.RadElement.RaiseRoutedEvent(RadElement sender, RoutedEventArgs args)
   at Telerik.WinControls.RadElement.DoMouseDown(MouseEventArgs e)
   at Telerik.WinControls.ComponentInputBehavior.OnMouseDown(MouseEventArgs e)
   at Telerik.WinControls.Spreadsheet.UI.RadSpreadsheetComponentInputBehavior.OnMouseDown(MouseEventArgs e)
   at Telerik.WinControls.RadControl.OnMouseDown(MouseEventArgs e)
   at System.Windows.Forms.Control.WmMouseDown(Message& m, MouseButtons button, Int32 clicks)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.ScrollableControl.WndProc(Message& m)
   at Telerik.WinControls.RadControl.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)