diff --git a/flatcamTools/ToolCalculators.py b/flatcamTools/ToolCalculators.py
index 6a5a494f..87a62290 100644
--- a/flatcamTools/ToolCalculators.py
+++ b/flatcamTools/ToolCalculators.py
@@ -243,8 +243,11 @@ class ToolCalculator(FlatCAMTool):
             if self.app.ui.splitter.sizes()[0] == 0:
                 self.app.ui.splitter.setSizes([1, 1])
             else:
-                if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
-                    self.app.ui.splitter.setSizes([0, 1])
+                try:
+                    if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
+                        self.app.ui.splitter.setSizes([0, 1])
+                except AttributeError:
+                    pass
 
         FlatCAMTool.run(self)
 
diff --git a/flatcamTools/ToolCutOut.py b/flatcamTools/ToolCutOut.py
index 9af3b285..744c0c8a 100644
--- a/flatcamTools/ToolCutOut.py
+++ b/flatcamTools/ToolCutOut.py
@@ -287,8 +287,11 @@ class CutOut(FlatCAMTool):
             if self.app.ui.splitter.sizes()[0] == 0:
                 self.app.ui.splitter.setSizes([1, 1])
             else:
-                if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
-                    self.app.ui.splitter.setSizes([0, 1])
+                try:
+                    if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
+                        self.app.ui.splitter.setSizes([0, 1])
+                except AttributeError:
+                    pass
 
         FlatCAMTool.run(self)
         self.set_tool_ui()
diff --git a/flatcamTools/ToolDblSided.py b/flatcamTools/ToolDblSided.py
index fa8486ed..c29ba9e7 100644
--- a/flatcamTools/ToolDblSided.py
+++ b/flatcamTools/ToolDblSided.py
@@ -277,8 +277,11 @@ class DblSidedTool(FlatCAMTool):
             if self.app.ui.splitter.sizes()[0] == 0:
                 self.app.ui.splitter.setSizes([1, 1])
             else:
-                if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
-                    self.app.ui.splitter.setSizes([0, 1])
+                try:
+                    if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
+                        self.app.ui.splitter.setSizes([0, 1])
+                except AttributeError:
+                    pass
 
         FlatCAMTool.run(self)
         self.set_tool_ui()
diff --git a/flatcamTools/ToolFilm.py b/flatcamTools/ToolFilm.py
index c01fcbbe..54b880c7 100644
--- a/flatcamTools/ToolFilm.py
+++ b/flatcamTools/ToolFilm.py
@@ -188,8 +188,11 @@ class Film(FlatCAMTool):
             if self.app.ui.splitter.sizes()[0] == 0:
                 self.app.ui.splitter.setSizes([1, 1])
             else:
-                if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
-                    self.app.ui.splitter.setSizes([0, 1])
+                try:
+                    if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
+                        self.app.ui.splitter.setSizes([0, 1])
+                except AttributeError:
+                    pass
 
         FlatCAMTool.run(self)
 
diff --git a/flatcamTools/ToolImage.py b/flatcamTools/ToolImage.py
index 09a209a0..b719fbd2 100644
--- a/flatcamTools/ToolImage.py
+++ b/flatcamTools/ToolImage.py
@@ -155,8 +155,11 @@ class ToolImage(FlatCAMTool):
             if self.app.ui.splitter.sizes()[0] == 0:
                 self.app.ui.splitter.setSizes([1, 1])
             else:
-                if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
-                    self.app.ui.splitter.setSizes([0, 1])
+                try:
+                    if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
+                        self.app.ui.splitter.setSizes([0, 1])
+                except AttributeError:
+                    pass
 
         FlatCAMTool.run(self)
         self.set_tool_ui()
diff --git a/flatcamTools/ToolNonCopperClear.py b/flatcamTools/ToolNonCopperClear.py
index d5b20819..561b56e9 100644
--- a/flatcamTools/ToolNonCopperClear.py
+++ b/flatcamTools/ToolNonCopperClear.py
@@ -262,6 +262,17 @@ class NonCopperClear(FlatCAMTool, Gerber):
     def run(self, toggle=True):
         self.app.report_usage("ToolNonCopperClear()")
 
+        if toggle:
+            # if the splitter is hidden, display it, else hide it but only if the current widget is the same
+            if self.app.ui.splitter.sizes()[0] == 0:
+                self.app.ui.splitter.setSizes([1, 1])
+            else:
+                try:
+                    if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
+                        self.app.ui.splitter.setSizes([0, 1])
+                except AttributeError:
+                    pass
+
         FlatCAMTool.run(self)
         self.set_tool_ui()
 
diff --git a/flatcamTools/ToolPaint.py b/flatcamTools/ToolPaint.py
index cab5e590..0e34189a 100644
--- a/flatcamTools/ToolPaint.py
+++ b/flatcamTools/ToolPaint.py
@@ -325,8 +325,11 @@ class ToolPaint(FlatCAMTool, Gerber):
             if self.app.ui.splitter.sizes()[0] == 0:
                 self.app.ui.splitter.setSizes([1, 1])
             else:
-                if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
-                    self.app.ui.splitter.setSizes([0, 1])
+                try:
+                    if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
+                        self.app.ui.splitter.setSizes([0, 1])
+                except AttributeError:
+                    pass
 
         FlatCAMTool.run(self)
         self.set_tool_ui()
diff --git a/flatcamTools/ToolPanelize.py b/flatcamTools/ToolPanelize.py
index 34cef26f..25c653a8 100644
--- a/flatcamTools/ToolPanelize.py
+++ b/flatcamTools/ToolPanelize.py
@@ -221,8 +221,11 @@ class Panelize(FlatCAMTool):
             if self.app.ui.splitter.sizes()[0] == 0:
                 self.app.ui.splitter.setSizes([1, 1])
             else:
-                if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
-                    self.app.ui.splitter.setSizes([0, 1])
+                try:
+                    if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
+                        self.app.ui.splitter.setSizes([0, 1])
+                except AttributeError:
+                    pass
 
         FlatCAMTool.run(self)
         self.set_tool_ui()
diff --git a/flatcamTools/ToolProperties.py b/flatcamTools/ToolProperties.py
index 979dc95d..765da0e5 100644
--- a/flatcamTools/ToolProperties.py
+++ b/flatcamTools/ToolProperties.py
@@ -75,8 +75,11 @@ class Properties(FlatCAMTool):
             if self.app.ui.splitter.sizes()[0] == 0:
                 self.app.ui.splitter.setSizes([1, 1])
             else:
-                if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
-                    self.app.ui.splitter.setSizes([0, 1])
+                try:
+                    if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
+                        self.app.ui.splitter.setSizes([0, 1])
+                except AttributeError:
+                    pass
 
         FlatCAMTool.run(self)
         self.set_tool_ui()
diff --git a/flatcamTools/ToolSolderPaste.py b/flatcamTools/ToolSolderPaste.py
index 425d688b..74287a50 100644
--- a/flatcamTools/ToolSolderPaste.py
+++ b/flatcamTools/ToolSolderPaste.py
@@ -434,8 +434,11 @@ class SolderPaste(FlatCAMTool):
             if self.app.ui.splitter.sizes()[0] == 0:
                 self.app.ui.splitter.setSizes([1, 1])
             else:
-                if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
-                    self.app.ui.splitter.setSizes([0, 1])
+                try:
+                    if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
+                        self.app.ui.splitter.setSizes([0, 1])
+                except AttributeError:
+                    pass
 
         FlatCAMTool.run(self)
         self.set_tool_ui()
diff --git a/flatcamTools/ToolTransform.py b/flatcamTools/ToolTransform.py
index a94ad101..a0a05367 100644
--- a/flatcamTools/ToolTransform.py
+++ b/flatcamTools/ToolTransform.py
@@ -383,8 +383,11 @@ class ToolTransform(FlatCAMTool):
             if self.app.ui.splitter.sizes()[0] == 0:
                 self.app.ui.splitter.setSizes([1, 1])
             else:
-                if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
-                    self.app.ui.splitter.setSizes([0, 1])
+                try:
+                    if self.app.ui.tool_scroll_area.widget().objectName() == self.toolName:
+                        self.app.ui.splitter.setSizes([0, 1])
+                except AttributeError:
+                    pass
 
         FlatCAMTool.run(self)
         self.set_tool_ui()