diff --git a/ExtendedWPFToolkitSolution/Src/Xceed.Wpf.AvalonDock/DockingManager.cs b/ExtendedWPFToolkitSolution/Src/Xceed.Wpf.AvalonDock/DockingManager.cs
index 2ed4f6c1f..860698090 100644
--- a/ExtendedWPFToolkitSolution/Src/Xceed.Wpf.AvalonDock/DockingManager.cs
+++ b/ExtendedWPFToolkitSolution/Src/Xceed.Wpf.AvalonDock/DockingManager.cs
@@ -295,7 +295,7 @@ void DockingManager_Loaded(object sender, RoutedEventArgs e)
                 SetupAutoHideWindow();
 
                 //load windows not already loaded!
-                foreach (var fw in Layout.FloatingWindows.Where(fw => !_fwList.Any(fwc => fwc.Model == fw)))
+                foreach (var fw in Layout.FloatingWindows.Where(fw => !_fwList.Any(fwc => fwc.Model == fw)).ToArray())
                     _fwList.Add(CreateUIElementForModel(fw) as LayoutFloatingWindowControl);
 
                 //create the overlaywindow if it's possible