diff --git a/src/Mod/Path/PathScripts/PathCircularHoleBase.py b/src/Mod/Path/PathScripts/PathCircularHoleBase.py
index fb122550ee..b56d576448 100644
--- a/src/Mod/Path/PathScripts/PathCircularHoleBase.py
+++ b/src/Mod/Path/PathScripts/PathCircularHoleBase.py
@@ -134,15 +134,20 @@ class ObjectOp(PathOp.ObjectOp):
             edge = self.getArchPanelEdge(obj, base, sub)
             return edge.BoundBox.XLength
 
-        shape = base.Shape.getElement(sub)
-        if shape.ShapeType == 'Vertex':
-            return 0
+        try:
+            shape = base.Shape.getElement(sub)
+            if shape.ShapeType == 'Vertex':
+                return 0
 
-        if shape.ShapeType == 'Edge' and type(shape.Curve) == Part.Circle:
-            return shape.Curve.Radius * 2
+            if shape.ShapeType == 'Edge' and type(shape.Curve) == Part.Circle:
+                return shape.Curve.Radius * 2
 
-        # for all other shapes the diameter is just the dimension in X
-        return shape.BoundBox.XLength
+            # for all other shapes the diameter is just the dimension in X
+            return shape.BoundBox.XLength
+        except Part.OCCError as e:
+            PathLog.error(e)
+
+        return 0
 
     def holePosition(self, obj, base, sub):
         '''holePosition(obj, base, sub) ... returns a Vector for the position defined by the given features.
@@ -184,7 +189,6 @@ class ObjectOp(PathOp.ObjectOp):
         calculated and assigned.
         Do not overwrite, implement circularHoleExecute(obj, holes) instead.'''
         PathLog.track()
-        PathLog.debug("\nopExecute() in PathCircularHoleBase.py")
 
         holes = []
         baseSubsTuples = []
@@ -364,6 +368,8 @@ class ObjectOp(PathOp.ObjectOp):
         pass # pylint: disable=unnecessary-pass
 
     def findAllHoles(self, obj):
+        '''findAllHoles(obj) ... find all holes of all base models and assign as features.'''
+        PathLog.track()
         if not self.getJob(obj):
             return
         features = []
diff --git a/src/Mod/Path/PathScripts/PathCircularHoleBaseGui.py b/src/Mod/Path/PathScripts/PathCircularHoleBaseGui.py
index 6a971e387b..4e77c0001e 100644
--- a/src/Mod/Path/PathScripts/PathCircularHoleBaseGui.py
+++ b/src/Mod/Path/PathScripts/PathCircularHoleBaseGui.py
@@ -81,7 +81,8 @@ class TaskPanelHoleGeometryPage(PathOpGui.TaskPanelBaseGeometryPage):
                 item.setData(self.DataObjectSub, sub)
                 self.form.baseList.setItem(self.form.baseList.rowCount()-1, 0, item)
 
-                item = QtGui.QTableWidgetItem("{:.3f}".format(obj.Proxy.holeDiameter(obj, base, sub)))
+                dia = obj.Proxy.holeDiameter(obj, base, sub)
+                item = QtGui.QTableWidgetItem("{:.3f}".format(dia))
                 item.setData(self.DataFeatureName, name)
                 item.setData(self.DataObject, base)
                 item.setData(self.DataObjectSub, sub)
diff --git a/src/Mod/Path/PathScripts/PathJobGui.py b/src/Mod/Path/PathScripts/PathJobGui.py
index ce09925b27..11efdef192 100644
--- a/src/Mod/Path/PathScripts/PathJobGui.py
+++ b/src/Mod/Path/PathScripts/PathJobGui.py
@@ -114,15 +114,17 @@ class ViewProvider:
         self.switch = None
         self.taskPanel = None
         self.vobj = None
-        self.baseVisibility = None
-        self.stockVisibility = None
+        self.baseVisibility = {}
+        self.stockVisibility = False
 
     def attach(self, vobj):
         self.vobj = vobj
         self.obj = vobj.Object
         self.taskPanel = None
-        self.baseVisibility = None
-        self.stockVisibility = None
+        if not hasattr(self, 'baseVisibility'):
+            self.baseVisibility = {}
+        if not hasattr(self, 'stockVisibility'):
+            self.stockVisibility = False
 
         # setup the axis display at the origin
         self.switch = coin.SoSwitch()