diff --git a/My Project/AssemblyInfo.vb b/My Project/AssemblyInfo.vb
index 2afb32e..e08c64f 100644
--- a/My Project/AssemblyInfo.vb	
+++ b/My Project/AssemblyInfo.vb	
@@ -70,6 +70,6 @@ Imports System.Windows
 ' by using the '*' as shown below:
 ' <Assembly: AssemblyVersion("1.0.*")> 
 
-<Assembly: AssemblyVersion("2.3.4.4")>
-<Assembly: AssemblyFileVersion("2.3.4.4")>
+<Assembly: AssemblyVersion("2.3.4.5")>
+<Assembly: AssemblyFileVersion("2.3.4.5")>
 
diff --git a/OptionPanel/DrawOptionPanel/ManageLayerExpander/LayerTreeView.vb b/OptionPanel/DrawOptionPanel/ManageLayerExpander/LayerTreeView.vb
index 3846fda..3014f1a 100644
--- a/OptionPanel/DrawOptionPanel/ManageLayerExpander/LayerTreeView.vb
+++ b/OptionPanel/DrawOptionPanel/ManageLayerExpander/LayerTreeView.vb
@@ -80,6 +80,23 @@ Public Class LayerTreeViewItem
                   Map.refProjectVM.ExecuteCommand(Controller.CMD.HIDE)
                End If
             End If
+            Dim bOnOffGroup As Boolean = ((Keyboard.Modifiers And ModifierKeys.Shift) = ModifierKeys.Shift) AndAlso Items.Count > 0
+            If bOnOffGroup Then
+               ' abilito/disabilito tutti i nodi del livello sotto di esso (e non oltre)
+               For Each Node In Items
+                  Node.m_bOnOff = value
+                  ' se abilitato, eseguo operazione
+                  If m_SendCmd Then
+                     Map.refProjectVM.SetLastInteger(Node.Id)
+                     If value Then
+                        Map.refProjectVM.ExecuteCommand(Controller.CMD.SHOW)
+                     Else
+                        Map.refProjectVM.ExecuteCommand(Controller.CMD.HIDE)
+                     End If
+                  End If
+                  Node.NotifyPropertyChanged(NameOf(OnOff))
+               Next
+            End If
          End If
       End Set
    End Property
diff --git a/OptionPanel/MachiningOptionPanel/OperationExpander/OperationListBoxItem/DispositionOpListBoxItem.vb b/OptionPanel/MachiningOptionPanel/OperationExpander/OperationListBoxItem/DispositionOpListBoxItem.vb
index e0fea9b..e82590c 100644
--- a/OptionPanel/MachiningOptionPanel/OperationExpander/OperationListBoxItem/DispositionOpListBoxItem.vb
+++ b/OptionPanel/MachiningOptionPanel/OperationExpander/OperationListBoxItem/DispositionOpListBoxItem.vb
@@ -23,7 +23,7 @@ Public Class DispositionOpListBoxItem
             Return
          End If
          For Each OpInDispIndex In OpIndexes
-            DirectCast(Map.refOperationsListExpanderVM.OperationList.Item(OpInDispIndex), MachiningOpListBoxItem).Status = value
+            DirectCast(Map.refOperationsListExpanderVM.OperationList.Item(OpInDispIndex), MachiningOpListBoxItem).Status = If(IsNothing(value), False, CBool(value))
          Next
       End Set
    End Property