diff --git a/AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/Connector/LogicalConnectorInfo.cs b/AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/Connector/LogicalConnectorInfo.cs
index 29b7203..9b92bbb 100644
--- a/AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/Connector/LogicalConnectorInfo.cs
+++ b/AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/Connector/LogicalConnectorInfo.cs
@@ -68,17 +68,22 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
         }
 
-        public ConnectorValueType _valueType;
+        public ConnectorValueType _connectorValueType;
         public ConnectorValueType ConnectorValueType
         {
             get
             {
-                return _valueType;
+                return _connectorValueType;
             }
             set
             {
-                SetProperty(ref _valueType, value);
+                SetProperty(ref _connectorValueType, value);
             }
         }
+
+        public bool IsError
+        {
+            get;set;
+        }
     }
 }
diff --git a/AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/DiagramViewModel.cs b/AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/DiagramViewModel.cs
index 7cc9d68..13db7b9 100644
--- a/AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/DiagramViewModel.cs
+++ b/AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/DiagramViewModel.cs
@@ -1420,6 +1420,7 @@ namespace AIStudio.Wpf.DiagramDesigner
             if (parameter is SelectableDesignerItemViewModelBase ite)
             {
                 ite.IsSelected = false;
+                ite.Dispose();
                 Items.Remove(ite);
             }
             else if (parameter is IEnumerable<SelectableDesignerItemViewModelBase> items)
@@ -1427,6 +1428,7 @@ namespace AIStudio.Wpf.DiagramDesigner
                 foreach (var item in items)
                 {
                     item.IsSelected = false;
+                    item.Dispose();
                     Items.Remove(item);
                 }
             }
@@ -1451,18 +1453,12 @@ namespace AIStudio.Wpf.DiagramDesigner
             if (olditems.Any())
             {
                 DoCommandManager.DoNewCommand(this.ToString(),
-                    () => {
-                        foreach (var item in olditems)
-                        {
-                            Items.Remove(item);
-                        }
-                    },
-                    () => {
-                        foreach (var item in olditems)
-                        {
-                            Items.Add(item);
-                        }
-                    });
+                   () => {
+                       Remove(olditems);
+                   },
+                   () => {
+                      Add(olditems);
+                   });
             }
         }
 
@@ -3040,27 +3036,33 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
             else if (DiagramOption.ShortcutOption.Copy(e))
             {
-                return Copy(null) != null;
+                CopyCommand.Execute(null);
+                return true;
             }
             else if (DiagramOption.ShortcutOption.Paste(e))
             {
-                return Paste(null) != null;
+                PasteCommand.Execute(null);
+                return true;
             }
             else if (DiagramOption.ShortcutOption.Cut(e))
             {
-                return Cut(null) != null;
+                CutCommand.Execute(null);
+                return true;
             }
             else if (DiagramOption.ShortcutOption.Undo(e))
             {
-                return Undo(null);
+                UndoCommand.Execute(null);
+                return true;
             }
             else if (DiagramOption.ShortcutOption.Redo(e))
             {
-                return Redo(null);
+                RedoCommand.Execute(null);
+                return true;
             }
             else if (DiagramOption.ShortcutOption.Delete(e))
             {
-                return Delete(null) != null;
+                DeleteCommand.Execute(null);
+                return true;
             }
             else if (DiagramOption.ShortcutOption.LeftMove(e))
             {
diff --git a/AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/SelectableViewModelBase.cs b/AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/SelectableViewModelBase.cs
index 336a23e..e8cb3ad 100644
--- a/AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/SelectableViewModelBase.cs
+++ b/AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/SelectableViewModelBase.cs
@@ -14,7 +14,7 @@ using Newtonsoft.Json;
 
 namespace AIStudio.Wpf.DiagramDesigner
 {
-    public abstract class SelectableViewModelBase : BindableBase, ISelectable
+    public abstract class SelectableViewModelBase : BindableBase, ISelectable, IDisposable
     {
         protected IDiagramServiceProvider _service
         {
diff --git a/AIStudio.Wpf.DiagramDesigner/ViewModels/DefaultViewModel/LogicalGateItemViewModelBase.cs b/AIStudio.Wpf.DiagramDesigner/ViewModels/DefaultViewModel/LogicalGateItemViewModelBase.cs
index ba8c988..989be5a 100644
--- a/AIStudio.Wpf.DiagramDesigner/ViewModels/DefaultViewModel/LogicalGateItemViewModelBase.cs
+++ b/AIStudio.Wpf.DiagramDesigner/ViewModels/DefaultViewModel/LogicalGateItemViewModelBase.cs
@@ -303,7 +303,11 @@ namespace AIStudio.Wpf.DiagramDesigner
         {
             foreach (var output in Output)
             {
-                if (output.Value.ConnectorValueType == ConnectorValueType.Bool)
+                if (output.Value.IsError)
+                {
+                    output.Value.ColorViewModel.FillColor.Color = Colors.Orange;
+                }
+                else if (output.Value.ConnectorValueType == ConnectorValueType.Bool)
                 {
                     if (output.Value.ConnectorValue == 0)
                     {