After I pressed "Add" button , and all of sudden SourceTree crashed.

I got this in my error log ( I think the English equivalent error message should be like " specified argument is out of range" ) :

System.String[]2013-07-12T11:33:19: Fatal error:
System.ArgumentOutOfRangeException: 指定的引數超出有效值的範圍。
參數名稱: index

2013-07-12T11:33:19: Stack trace:
於 System.Windows.Media.VisualCollection.get_Item(Int32 index)
於 System.Windows.Controls.UIElementCollection.get_Item(Int32 index)
於 System.Windows.Controls.Panel.GetVisualChild(Int32 index)
於 System.Windows.Media.Visual.InternalGet2DOr3DVisualChild(Int32 index)
於 System.Windows.Media.VisualTreeHelper.GetChild(DependencyObject reference, Int32 childIndex)
於 GongSolutions.Wpf.DragDrop.Utilities.ItemsControlExtensions.GetItemContainerType(ItemsControl itemsControl)
於 GongSolutions.Wpf.DragDrop.Utilities.ItemsControlExtensions.GetItemContainer(ItemsControl itemsControl, UIElement child)
於 GongSolutions.Wpf.DragDrop.DragInfo..ctor(Object sender, MouseButtonEventArgs e)
於 GongSolutions.Wpf.DragDrop.DragDrop.DragSource_PreviewMouseLeftButtonDown(Object sender, MouseButtonEventArgs e)
於 System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
於 System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
於 System.Windows.UIElement.ReRaiseEventAs(DependencyObject sender, RoutedEventArgs args, RoutedEvent newEvent)
於 System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
於 System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
於 System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
於 System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
於 System.Windows.Input.InputManager.ProcessStagingArea()
於 System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport)
於 System.Windows.Interop.HwndMouseInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawMouseActions actions, Int32 x, Int32 y, Int32 wheel)
於 System.Windows.Interop.HwndMouseInputProvider.FilterMessage(IntPtr hwnd, WindowMessage msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
於 System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
於 MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
於 MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
於 System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
於 MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)