Do not show duplicate menu when no object is selected.

diff --git a/Cura/gui/sceneView.py b/Cura/gui/sceneView.py
index 3241fc0e3daf7b20f89db47ab68d6dedbe2a5a66..5fe0ebeb462b3febf5ecb4f254f16faa765abb74 100644 (file)
--- a/Cura/gui/sceneView.py
+++ b/Cura/gui/sceneView.py
@@ -345,7 +345,7 @@ class SceneView(openglGui.glGuiPanel):
                                        self._selectedObj = None
                                        self.Refresh()
                        if e.GetButton() == 3:
-                               if self._selectedObj == self._focusObj:
+                               if self._selectedObj is not None and self._selectedObj == self._focusObj:
                                        menu = wx.Menu()
                                        self.Bind(wx.EVT_MENU, self.OnDuplicateObject, menu.Append(-1, 'Duplicate'))
                                        self.PopupMenu(menu)