diff --git a/CHANGELOG.md b/CHANGELOG.md
index c84aa05..66ef747 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Changelog
 
+## 22/01/2021 - v2.3.2
+
+* (Add) Settings - Automations: Change only light-off delay if value is zero (Enabled by default)
+* (Fix) Calibrators: Some file formats will crash when calibration test output more layers than the dummy file
+* (Fix) Undo/redo don't unlock the save function
+
 ## 19/01/2021 - v2.3.1
 
 * (Add) Calibrator - Stress Tower: Generates a stress tower to test the printer capabilities
diff --git a/CREDITS.md b/CREDITS.md
index 2d9d6c9..6cd8b3c 100644
--- a/CREDITS.md
+++ b/CREDITS.md
@@ -42,4 +42,5 @@
 * Timothy Gray
 * David Gordon
 * Claus Pfeilschifter
-* Chris Taatgen
\ No newline at end of file
+* Chris Taatgen
+* Andrew Griffiths
\ No newline at end of file
diff --git a/UVtools.Core/Layer/LayerManager.cs b/UVtools.Core/Layer/LayerManager.cs
index a9841ce..a5ec45d 100644
--- a/UVtools.Core/Layer/LayerManager.cs
+++ b/UVtools.Core/Layer/LayerManager.cs
@@ -43,6 +43,7 @@ namespace UVtools.Core
                 _layers = value;
                 BoundingRectangle = Rectangle.Empty;
                 SlicerFile.LayerCount = Count;
+                SlicerFile.RequireFullEncode = true;
                 if (value is null) return;
                 SlicerFile.PrintTime = SlicerFile.PrintTimeComputed;
             }
@@ -187,19 +188,64 @@ namespace UVtools.Core
             {
                 var layer = this[layerIndex];
                 layer.Index = layerIndex;
-                
-                if(property is null || property == nameof(SlicerFile.BottomExposureTime) || property == nameof(SlicerFile.ExposureTime))
-                    layer.ExposureTime  = SlicerFile.GetInitialLayerValueOrNormal(layerIndex, SlicerFile.BottomExposureTime, SlicerFile.ExposureTime);
-                if (property is null || property == nameof(SlicerFile.BottomLiftHeight) || property == nameof(SlicerFile.LiftHeight))
-                    layer.LiftHeight    = SlicerFile.GetInitialLayerValueOrNormal(layerIndex, SlicerFile.BottomLiftHeight, SlicerFile.LiftHeight);
-                if (property is null || property == nameof(SlicerFile.BottomLiftSpeed) || property == nameof(SlicerFile.LiftSpeed))
-                    layer.LiftSpeed     = SlicerFile.GetInitialLayerValueOrNormal(layerIndex, SlicerFile.BottomLiftSpeed, SlicerFile.LiftSpeed);
-                if (property is null || property == nameof(SlicerFile.RetractSpeed))
-                    layer.RetractSpeed  = SlicerFile.RetractSpeed;
-                if (property is null || property == nameof(SlicerFile.BottomLightPWM) || property == nameof(SlicerFile.LightPWM))
-                    layer.LightPWM      = SlicerFile.GetInitialLayerValueOrNormal(layerIndex, SlicerFile.BottomLightPWM, SlicerFile.LightPWM);
-                if (property is null || property == nameof(SlicerFile.BottomLightOffDelay) || property == nameof(SlicerFile.LightOffDelay))
+
+                if (property is null)
+                {
+                    layer.ExposureTime = SlicerFile.GetInitialLayerValueOrNormal(layerIndex, SlicerFile.BottomExposureTime, SlicerFile.ExposureTime);
+                    layer.LiftHeight = SlicerFile.GetInitialLayerValueOrNormal(layerIndex, SlicerFile.BottomLiftHeight, SlicerFile.LiftHeight);
+                    layer.LiftSpeed = SlicerFile.GetInitialLayerValueOrNormal(layerIndex, SlicerFile.BottomLiftSpeed, SlicerFile.LiftSpeed);
+                    layer.RetractSpeed = SlicerFile.RetractSpeed;
+                    layer.LightPWM = SlicerFile.GetInitialLayerValueOrNormal(layerIndex, SlicerFile.BottomLightPWM, SlicerFile.LightPWM);
                     layer.LightOffDelay = SlicerFile.GetInitialLayerValueOrNormal(layerIndex, SlicerFile.BottomLightOffDelay, SlicerFile.LightOffDelay);
+                }
+                else
+                {
+                    if (layer.IsNormalLayer)
+                    {
+                        switch (property)
+                        {
+                            case nameof(SlicerFile.ExposureTime):
+                                layer.ExposureTime = SlicerFile.ExposureTime;
+                                break;
+                            case nameof(SlicerFile.LiftHeight):
+                                layer.LiftHeight = SlicerFile.LiftHeight;
+                                break;
+                            case nameof(SlicerFile.LiftSpeed):
+                                layer.LiftSpeed = SlicerFile.LiftSpeed;
+                                break;
+                            case nameof(SlicerFile.LightOffDelay):
+                                layer.LightOffDelay = SlicerFile.LightOffDelay;
+                                break;
+                            case nameof(SlicerFile.LightPWM):
+                                layer.LightPWM = SlicerFile.LightPWM;
+                                break;
+                        }
+                    }
+                    else // Bottom layers
+                    {
+                        switch (property)
+                        {
+                            case nameof(SlicerFile.BottomExposureTime):
+                                layer.ExposureTime = SlicerFile.BottomExposureTime;
+                                break;
+                            case nameof(SlicerFile.BottomLiftHeight):
+                                layer.LiftHeight = SlicerFile.BottomLiftHeight;
+                                break;
+                            case nameof(SlicerFile.BottomLiftSpeed):
+                                layer.LiftSpeed = SlicerFile.BottomLiftSpeed;
+                                break;
+                            case nameof(SlicerFile.RetractSpeed):
+                                layer.RetractSpeed = SlicerFile.RetractSpeed;
+                                break;
+                            case nameof(SlicerFile.BottomLightOffDelay):
+                                layer.LightOffDelay = SlicerFile.BottomLightOffDelay;
+                                break;
+                            case nameof(SlicerFile.BottomLightPWM):
+                                layer.LightPWM = SlicerFile.BottomLightPWM;
+                                break;
+                        }
+                    }
+                }
 
                 if (recalculateZPos)
                 {
diff --git a/UVtools.Core/Operations/OperationLayerClone.cs b/UVtools.Core/Operations/OperationLayerClone.cs
index 211cb7d..5ec7c28 100644
--- a/UVtools.Core/Operations/OperationLayerClone.cs
+++ b/UVtools.Core/Operations/OperationLayerClone.cs
@@ -108,7 +108,6 @@ namespace UVtools.Core.Operations
             }
 
             slicerFile.LayerManager.Layers = layers;
-            slicerFile.RequireFullEncode = true;
 
             progress.Token.ThrowIfCancellationRequested();
 
diff --git a/UVtools.Core/Operations/OperationLayerImport.cs b/UVtools.Core/Operations/OperationLayerImport.cs
index 7e5b822..a540004 100644
--- a/UVtools.Core/Operations/OperationLayerImport.cs
+++ b/UVtools.Core/Operations/OperationLayerImport.cs
@@ -495,7 +495,6 @@ namespace UVtools.Core.Operations
 
             slicerFile.LayerManager.RebuildLayersProperties();
             slicerFile.SuppressRebuildProperties = false;
-            slicerFile.RequireFullEncode = true;
 
             return true;
         }
diff --git a/UVtools.Core/Operations/OperationLayerReHeight.cs b/UVtools.Core/Operations/OperationLayerReHeight.cs
index fb04a34..bcd93d5 100644
--- a/UVtools.Core/Operations/OperationLayerReHeight.cs
+++ b/UVtools.Core/Operations/OperationLayerReHeight.cs
@@ -173,7 +173,6 @@ namespace UVtools.Core.Operations
 
             slicerFile.LayerManager.Layers = layers;
             slicerFile.LayerHeight = (float)Item.LayerHeight;
-            slicerFile.RequireFullEncode = true;
 
             return true;
         }
diff --git a/UVtools.Core/Operations/OperationLayerRemove.cs b/UVtools.Core/Operations/OperationLayerRemove.cs
index 45816dd..5fa1907 100644
--- a/UVtools.Core/Operations/OperationLayerRemove.cs
+++ b/UVtools.Core/Operations/OperationLayerRemove.cs
@@ -104,7 +104,6 @@ namespace UVtools.Core.Operations
             }
 
             slicerFile.LayerManager.Layers = layers;
-            slicerFile.RequireFullEncode = true;
 
             return true;
         }
diff --git a/UVtools.Core/UVtools.Core.csproj b/UVtools.Core/UVtools.Core.csproj
index 2131a03..9bfaefd 100644
--- a/UVtools.Core/UVtools.Core.csproj
+++ b/UVtools.Core/UVtools.Core.csproj
@@ -10,7 +10,7 @@
     <RepositoryUrl>https://github.com/sn4k3/UVtools</RepositoryUrl>
     <PackageProjectUrl>https://github.com/sn4k3/UVtools</PackageProjectUrl>
     <Description>MSLA/DLP, file analysis, calibration, repair, conversion and manipulation</Description>
-    <Version>2.3.1</Version>
+    <Version>2.3.2</Version>
     <Copyright>Copyright © 2020 PTRTECH</Copyright>
     <PackageIcon>UVtools.png</PackageIcon>
     <Platforms>AnyCPU;x64</Platforms>
diff --git a/UVtools.WPF/MainWindow.Clipboard.cs b/UVtools.WPF/MainWindow.Clipboard.cs
index 6ef670c..bf8435d 100644
--- a/UVtools.WPF/MainWindow.Clipboard.cs
+++ b/UVtools.WPF/MainWindow.Clipboard.cs
@@ -51,6 +51,7 @@ namespace UVtools.WPF
 
         public void ClipboardUndo()
         {
+            CanSave = true;
             if ((_globalModifiers & KeyModifiers.Shift) != 0)
             {
                 ClipboardUndo(true);
@@ -61,6 +62,7 @@ namespace UVtools.WPF
 
         public async void ClipboardUndo(bool rerun)
         {
+            CanSave = true;
             var clip = Clipboard.CurrentClip;
             Clipboard.Undo();
             if (!rerun)
@@ -72,9 +74,16 @@ namespace UVtools.WPF
             if (operation is null)
             {
                 Clipboard.Redo();
+                CanSave = false;
             }
         }
 
+        public void ClipboardRedo()
+        {
+            CanSave = true;
+            Clipboard.Redo();
+        }
+
         public async void ClipboardClear()
         {
             if (await this.MessageBoxQuestion("Are you sure you want to clear the clipboard?\n" +
diff --git a/UVtools.WPF/MainWindow.axaml b/UVtools.WPF/MainWindow.axaml
index 70439b9..f2dcee6 100644
--- a/UVtools.WPF/MainWindow.axaml
+++ b/UVtools.WPF/MainWindow.axaml
@@ -1451,7 +1451,7 @@
 
             <Button
               IsEnabled="{Binding Clipboard.CanRedo}"
-              Command="{Binding Clipboard.Redo}"
+              Command="{Binding ClipboardRedo}"
               HotKey="Ctrl + Y"
               ToolTip.Tip="Redo [Ctrl + Y]"
                     >
diff --git a/UVtools.WPF/MainWindow.axaml.cs b/UVtools.WPF/MainWindow.axaml.cs
index 1118a95..f2b4647 100644
--- a/UVtools.WPF/MainWindow.axaml.cs
+++ b/UVtools.WPF/MainWindow.axaml.cs
@@ -1001,9 +1001,12 @@ namespace UVtools.WPF
             }
 
             bool modified = false;
-            if (Settings.Automations.BottomLightOffDelay > 0 &&
+            if (
+                Settings.Automations.BottomLightOffDelay > 0 &&
                 SlicerFile.PrintParameterModifiers is not null &&
-                SlicerFile.PrintParameterModifiers.Contains(FileFormat.PrintParameterModifier.BottomLightOffDelay))
+                SlicerFile.PrintParameterModifiers.Contains(FileFormat.PrintParameterModifier.BottomLightOffDelay) &&
+                (!Settings.Automations.ChangeOnlyLightOffDelayIfZero || Settings.Automations.ChangeOnlyLightOffDelayIfZero && SlicerFile.BottomLightOffDelay <= 0)
+                )
             {
                 var lightOff = OperationCalculator.LightOffDelayC.CalculateSeconds(SlicerFile.BottomLiftHeight,
                     SlicerFile.BottomLiftSpeed, SlicerFile.RetractSpeed, (float)Settings.Automations.BottomLightOffDelay);
@@ -1016,7 +1019,8 @@ namespace UVtools.WPF
 
             if (Settings.Automations.LightOffDelay > 0 &&
                 SlicerFile.PrintParameterModifiers is not null &&
-                SlicerFile.PrintParameterModifiers.Contains(FileFormat.PrintParameterModifier.LightOffDelay))
+                SlicerFile.PrintParameterModifiers.Contains(FileFormat.PrintParameterModifier.LightOffDelay) &&
+                (!Settings.Automations.ChangeOnlyLightOffDelayIfZero || Settings.Automations.ChangeOnlyLightOffDelayIfZero && SlicerFile.LightOffDelay <= 0))
             {
                 var lightOff = OperationCalculator.LightOffDelayC.CalculateSeconds(SlicerFile.LiftHeight,
                     SlicerFile.LiftSpeed, SlicerFile.RetractSpeed, (float)Settings.Automations.LightOffDelay);
diff --git a/UVtools.WPF/UVtools.WPF.csproj b/UVtools.WPF/UVtools.WPF.csproj
index 4c56924..3db6b4e 100644
--- a/UVtools.WPF/UVtools.WPF.csproj
+++ b/UVtools.WPF/UVtools.WPF.csproj
@@ -12,7 +12,7 @@
     <PackageLicenseFile>LICENSE</PackageLicenseFile>
     <RepositoryUrl>https://github.com/sn4k3/UVtools</RepositoryUrl>
     <RepositoryType>Git</RepositoryType>
-    <Version>2.3.1</Version>
+    <Version>2.3.2</Version>
   </PropertyGroup>
   
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
diff --git a/UVtools.WPF/UserSettings.cs b/UVtools.WPF/UserSettings.cs
index 16b0ff5..d8686dd 100644
--- a/UVtools.WPF/UserSettings.cs
+++ b/UVtools.WPF/UserSettings.cs
@@ -1047,6 +1047,7 @@ namespace UVtools.WPF
         {
             private bool _saveFileAfterModifications = true;
             private bool _autoConvertSl1Files = true;
+            private bool _changeOnlyLightOffDelayIfZero = true;
             private decimal _lightOffDelay = 2.5m;
             private decimal _bottomLightOffDelay = 3m;
 
@@ -1062,6 +1063,12 @@ namespace UVtools.WPF
                 set => RaiseAndSetIfChanged(ref _autoConvertSl1Files, value);
             }
 
+            public bool ChangeOnlyLightOffDelayIfZero
+            {
+                get => _changeOnlyLightOffDelayIfZero;
+                set => RaiseAndSetIfChanged(ref _changeOnlyLightOffDelayIfZero, value);
+            }
+
 
             public decimal LightOffDelay
             {
diff --git a/UVtools.WPF/Windows/SettingsWindow.axaml b/UVtools.WPF/Windows/SettingsWindow.axaml
index fe46049..db86adf 100644
--- a/UVtools.WPF/Windows/SettingsWindow.axaml
+++ b/UVtools.WPF/Windows/SettingsWindow.axaml
@@ -11,8 +11,7 @@
         SizeToContent="Height"
         CanResize="False"
         Title="UVtools - Settings"
-        Icon="/Assets/Icons/UVtools.ico"
-        >
+        Icon="/Assets/Icons/UVtools.ico">
   <StackPanel Orientation="Vertical" Spacing="10">
     <TabControl SelectedIndex="{Binding SelectedTabIndex}">
       <TabItem Header="General" VerticalContentAlignment="Center">
@@ -21,8 +20,7 @@
             <Border
               Margin="5"
             BorderBrush="LightBlue"
-            BorderThickness="4"
-          >
+            BorderThickness="4">
 
               <StackPanel Orientation="Vertical">
                 <TextBlock Padding="10" Background="LightBlue" FontWeight="Bold" Text="Startup"/>
@@ -1332,6 +1330,13 @@
 
                   <StackPanel Orientation="Vertical">
                       <TextBlock Padding="10" Background="LightBlue" FontWeight="Bold" Text="Light-off delay"/>
+
+                      <CheckBox Margin="15,15,15,0"
+                                Content="Change only light-off delay if value is zero"
+                                ToolTip.Tip="If enabled, it will only change light-off delay to the defined values if the original value is zero.
+&#x0a;If disabled, it will always change the light-off delay to the defined values."
+                                IsChecked="{Binding Settings.Automations.ChangeOnlyLightOffDelayIfZero}"/>
+
                       <Grid Margin="15"
                             RowDefinitions="Auto"
                             ColumnDefinitions="Auto,10,100,5,Auto,30,Auto,10,100,5,Auto">