diff --git a/EduNetworkBuilder/NetworkBuilder.cs b/EduNetworkBuilder/NetworkBuilder.cs
index 9aa0696..1328be1 100644
--- a/EduNetworkBuilder/NetworkBuilder.cs
+++ b/EduNetworkBuilder/NetworkBuilder.cs
@@ -2206,6 +2206,7 @@ namespace EduNetworkBuilder
 
         private void optionsToolStripMenuItem_Click(object sender, EventArgs e)
         {
+            ProcessChange(); //make sure we make an undo-point in case a change is made.
             OptionsWindow tWindow = new OptionsWindow(myNetwork);
             tWindow.ShowDialog();
             myNetwork.UpdateDeviceSizes();
diff --git a/EduNetworkBuilder/TraversalClass.cs b/EduNetworkBuilder/TraversalClass.cs
index fa8380f..4e5bf0d 100644
--- a/EduNetworkBuilder/TraversalClass.cs
+++ b/EduNetworkBuilder/TraversalClass.cs
@@ -9,6 +9,7 @@ namespace EduNetworkBuilder
     [Serializable]
     public class TraversalClass
     {
+        [Serializable]
         protected struct TraversalRecord
         {
             public string host;