2015-02-20T12:30:43: Fatal error: 
System.InvalidOperationException: Sequence contains no elements

2015-02-20T12:30:43: Stack trace: 
   at System.Linq.Enumerable.First[TSource](IEnumerable`1 source)
   at System.Windows.Controls.SelectionMultiple.SelectCore(MultiSelectTreeViewItem item) in c:\projects\atlassian.com\dev\bitbucket.org\sourcetreewin\Dependencies\MultiSelectTreeView\Controls\SelectionMultiple.cs:line 146
   at System.Windows.Controls.MultiSelectTreeViewItem.OnMouseDown(MouseButtonEventArgs e) in c:\projects\atlassian.com\dev\bitbucket.org\sourcetreewin\Dependencies\MultiSelectTreeView\Controls\MultiSelectTreeViewItem.cs:line 735
   at System.Windows.UIElement.OnMouseDownThunk(Object sender, MouseButtonEventArgs e)
   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.ContentElement.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)