Cannot edit a tree

EduNetworkBuilder/Network.cs

@@ -495,8 +495,8 @@ namespace EduNetworkBuilder
                 if (tItem.GetType().ToString() == "EduNetworkBuilder.NetworkDevice")
                 {
                     tDevice = (NetworkDevice)tItem;
-                    if (tDevice.AtLocation(NetworkLocation)) 
-                        return tDevice;
+                    if (tDevice.AtLocation(NetworkLocation) && tDevice.GetNetType() != NetworkComponentType.tree) 
+                        return tDevice; //We do not return trees.  Trees cannot be edited
                 }
             }
             return null;