Merge remote-tracking branch 'origin/#83_Editor_Dock_Crash' into development

Author: maxijabase

UI/MainWindow.xaml.cs

@@ -228,6 +228,7 @@ private void DockingPaneGroup_ChildrenTreeChanged(object sender, ChildrenTreeCha
             // Solution: Set the active LayoutDocumentPane to the first LayoutDocumentPaneGroup avilable child.
             if (e.Change == ChildrenTreeChange.DirectChildrenChanged
                 && !DockingPaneGroup.Children.Contains(DockingPane)
+                && DockingPaneGroup.Children.Count > 0
                 && DockingPaneGroup.Children[0] is LayoutDocumentPane pane)
             {
                 DockingPane = pane;