diff --git a/add_mesh_BoltFactory/Boltfactory.py b/add_mesh_BoltFactory/Boltfactory.py
index 244d97203c8733c3a44d7574714a96022e1e7c14..330df8ae15304f7b04df22cb1c8d4fb9419ccaf1 100644
--- a/add_mesh_BoltFactory/Boltfactory.py
+++ b/add_mesh_BoltFactory/Boltfactory.py
@@ -428,7 +428,8 @@ class add_mesh_bolt(Operator, AddObjectHelper):
 
         if bpy.context.mode == "OBJECT":
             if context.selected_objects != [] and context.active_object and \
-            ('Bolt' in context.active_object.data.keys()) and (self.change == True):
+                (context.active_object.data is not None) and ('Bolt' in context.active_object.data.keys()) and \
+                (self.change == True):
                 obj = context.active_object
                 oldmesh = obj.data
                 oldmeshname = obj.data.name
diff --git a/add_mesh_extra_objects/Wallfactory.py b/add_mesh_extra_objects/Wallfactory.py
index 4b15b62ac44b2adcb5cd23c9f0d061c232d1d647..9ed8cb84ddefc224c0ebf74c652988ad1078d37e 100644
--- a/add_mesh_extra_objects/Wallfactory.py
+++ b/add_mesh_extra_objects/Wallfactory.py
@@ -885,7 +885,8 @@ class add_mesh_wallb(Operator, object_utils.AddObjectHelper):
 
         if bpy.context.mode == "OBJECT":
             if context.selected_objects != [] and context.active_object and \
-            ('Wall' in context.active_object.data.keys()) and (self.change == True):
+                (context.active_object.data is not None) and ('Wall' in context.active_object.data.keys()) and \
+                (self.change == True):
                 obj = context.active_object
                 oldmesh = obj.data
                 oldmeshname = obj.data.name
diff --git a/add_mesh_extra_objects/add_mesh_beam_builder.py b/add_mesh_extra_objects/add_mesh_beam_builder.py
index 5bb1bceb2733a006922b4427749edd9ef9ea288d..0cc43e0f8471997706117d56bb59e20743896df8 100644
--- a/add_mesh_extra_objects/add_mesh_beam_builder.py
+++ b/add_mesh_extra_objects/add_mesh_beam_builder.py
@@ -761,7 +761,8 @@ class addBeam(Operator, object_utils.AddObjectHelper):
         if bpy.context.mode == "OBJECT":
 
             if context.selected_objects != [] and context.active_object and \
-            ('Beam' in context.active_object.data.keys()) and (self.change == True):
+                (context.active_object.data is not None) and ('Beam' in context.active_object.data.keys()) and \
+                (self.change == True):
                 obj = context.active_object
                 oldmesh = obj.data
                 oldmeshname = obj.data.name
diff --git a/add_mesh_extra_objects/add_mesh_gears.py b/add_mesh_extra_objects/add_mesh_gears.py
index 9655dea9f8c65916a91c925b5988def51f2dbc77..1d3bc70ec94f39ba94e53e83b5752b3d2389de1d 100644
--- a/add_mesh_extra_objects/add_mesh_gears.py
+++ b/add_mesh_extra_objects/add_mesh_gears.py
@@ -689,7 +689,8 @@ class AddGear(Operator, object_utils.AddObjectHelper):
 
         if bpy.context.mode == "OBJECT":
             if context.selected_objects != [] and context.active_object and \
-            ('Gear' in context.active_object.data.keys()) and (self.change == True):
+                (context.active_object.data is not None) and ('Gear' in context.active_object.data.keys()) and \
+                (self.change == True):
                 obj = context.active_object
                 oldmesh = obj.data
                 oldmeshname = obj.data.name
@@ -910,7 +911,8 @@ class AddWormGear(Operator, object_utils.AddObjectHelper):
 
         if bpy.context.mode == "OBJECT":
             if context.selected_objects != [] and context.active_object and \
-            ('WormGear' in context.active_object.data.keys()) and (self.change == True):
+                (context.active_object.data is not None) and ('WormGear' in context.active_object.data.keys()) and \
+                (self.change == True):
                 obj = context.active_object
                 oldmesh = obj.data
                 oldmeshname = obj.data.name
diff --git a/add_mesh_extra_objects/add_mesh_gemstones.py b/add_mesh_extra_objects/add_mesh_gemstones.py
index fe31675df146ed893705313c8a8c182a081c17a1..dc505b0f9a57c340b0c43bbe48add7a015a51131 100644
--- a/add_mesh_extra_objects/add_mesh_gemstones.py
+++ b/add_mesh_extra_objects/add_mesh_gemstones.py
@@ -284,7 +284,8 @@ class AddDiamond(Operator, object_utils.AddObjectHelper):
 
         if bpy.context.mode == "OBJECT":
             if context.selected_objects != [] and context.active_object and \
-            ('Diamond' in context.active_object.data.keys()) and (self.change == True):
+                (context.active_object.data is not None) and ('Diamond' in context.active_object.data.keys()) and \
+                (self.change == True):
                 obj = context.active_object
                 oldmesh = obj.data
                 oldmeshname = obj.data.name
@@ -433,7 +434,8 @@ class AddGem(Operator, object_utils.AddObjectHelper):
 
         if bpy.context.mode == "OBJECT":
             if context.selected_objects != [] and context.active_object and \
-            ('Gem' in context.active_object.data.keys()) and (self.change == True):
+                (context.active_object.data is not None) and ('Gem' in context.active_object.data.keys()) and \
+                (self.change == True):
                 obj = context.active_object
                 oldmesh = obj.data
                 oldmeshname = obj.data.name
diff --git a/add_mesh_extra_objects/add_mesh_honeycomb.py b/add_mesh_extra_objects/add_mesh_honeycomb.py
index 48a7194013a429e64bac4d15bfcd32a25aed716d..bb6734a4c209f9e8fa3e6bc49650aae3cd5c92e9 100644
--- a/add_mesh_extra_objects/add_mesh_honeycomb.py
+++ b/add_mesh_extra_objects/add_mesh_honeycomb.py
@@ -278,7 +278,8 @@ class add_mesh_honeycomb(bpy.types.Operator, object_utils.AddObjectHelper):
 
         if bpy.context.mode == "OBJECT":
             if context.selected_objects != [] and context.active_object and \
-            ('HoneyComb' in context.active_object.data.keys()) and (self.change == True):
+                (context.active_object.data is not None) and ('HoneyComb' in context.active_object.data.keys()) and \
+                (self.change == True):
                 obj = context.active_object
                 oldmesh = obj.data
                 oldmeshname = obj.data.name
diff --git a/add_mesh_extra_objects/add_mesh_pipe_joint.py b/add_mesh_extra_objects/add_mesh_pipe_joint.py
index 984213315134282b8aa347cf02519d39dbecf249..91c64e2fc3fda2eb2d4e682fba3f8f45377e6df0 100644
--- a/add_mesh_extra_objects/add_mesh_pipe_joint.py
+++ b/add_mesh_extra_objects/add_mesh_pipe_joint.py
@@ -230,7 +230,8 @@ class AddElbowJoint(Operator, object_utils.AddObjectHelper):
 
         if bpy.context.mode == "OBJECT":
             if (context.selected_objects != []) and context.active_object and \
-            ('ElbowJoint' in context.active_object.data.keys()) and (self.change == True):
+                (context.active_object.data is not None) and ('ElbowJoint' in context.active_object.data.keys()) and \
+                (self.change == True):
                 obj = context.active_object
                 oldmesh = obj.data
                 oldmeshname = obj.data.name
@@ -496,7 +497,8 @@ class AddTeeJoint(Operator, object_utils.AddObjectHelper):
 
         if bpy.context.mode == "OBJECT":
             if (context.selected_objects != []) and context.active_object and \
-            ('TeeJoint' in context.active_object.data.keys()) and (self.change == True):
+                (context.active_object.data is not None) and ('TeeJoint' in context.active_object.data.keys()) and \
+                (self.change == True):
                 obj = context.active_object
                 oldmesh = obj.data
                 oldmeshname = obj.data.name
@@ -779,7 +781,8 @@ class AddWyeJoint(Operator, object_utils.AddObjectHelper):
 
         if bpy.context.mode == "OBJECT":
             if (context.selected_objects != []) and context.active_object and \
-            ('WyeJoint' in context.active_object.data.keys()) and (self.change == True):
+                (context.active_object.data is not None) and ('WyeJoint' in context.active_object.data.keys()) and \
+                (self.change == True):
                 obj = context.active_object
                 oldmesh = obj.data
                 oldmeshname = obj.data.name
@@ -1126,7 +1129,8 @@ class AddCrossJoint(Operator, object_utils.AddObjectHelper):
 
         if bpy.context.mode == "OBJECT":
             if (context.selected_objects != []) and context.active_object and \
-            ('CrossJoint' in context.active_object.data.keys()) and (self.change == True):
+                (context.active_object.data is not None) and ('CrossJoint' in context.active_object.data.keys()) and \
+                (self.change == True):
                 obj = context.active_object
                 oldmesh = obj.data
                 oldmeshname = obj.data.name
@@ -1370,7 +1374,8 @@ class AddNJoint(Operator, object_utils.AddObjectHelper):
 
         if bpy.context.mode == "OBJECT":
             if (context.selected_objects != []) and context.active_object and \
-            ('NJoint' in context.active_object.data.keys()) and (self.change == True):
+                (context.active_object.data is not None) and ('NJoint' in context.active_object.data.keys()) and \
+                (self.change == True):
                 obj = context.active_object
                 oldmesh = obj.data
                 oldmeshname = obj.data.name
diff --git a/add_mesh_extra_objects/add_mesh_pyramid.py b/add_mesh_extra_objects/add_mesh_pyramid.py
index 405e6eaf13e87380c140f40780a05ab1ebaed172..58fafb04762d138b27433428792dbb2f7d5f0db8 100644
--- a/add_mesh_extra_objects/add_mesh_pyramid.py
+++ b/add_mesh_extra_objects/add_mesh_pyramid.py
@@ -168,7 +168,8 @@ class AddPyramid(bpy.types.Operator,  object_utils.AddObjectHelper):
 
         if bpy.context.mode == "OBJECT":
             if context.selected_objects != [] and context.active_object and \
-            ('Pyramid' in context.active_object.data.keys()) and (self.change == True):
+                (context.active_object.data is not None) and ('Pyramid' in context.active_object.data.keys()) and \
+                (self.change == True):
                 obj = context.active_object
                 oldmesh = obj.data
                 oldmeshname = obj.data.name
diff --git a/add_mesh_extra_objects/add_mesh_round_brilliant.py b/add_mesh_extra_objects/add_mesh_round_brilliant.py
index e50a1dbe52afae722f931baea0f93f6aea32dff4..874a26dba0f7a16c3795ca82692fad83fd1c6d71 100644
--- a/add_mesh_extra_objects/add_mesh_round_brilliant.py
+++ b/add_mesh_extra_objects/add_mesh_round_brilliant.py
@@ -428,7 +428,8 @@ class MESH_OT_primitive_brilliant_add(Operator, object_utils.AddObjectHelper):
 
         if bpy.context.mode == "OBJECT":
             if context.selected_objects != [] and context.active_object and \
-            ('Brilliant' in context.active_object.data.keys()) and (self.change == True):
+                (context.active_object.data is not None) and ('Brilliant' in context.active_object.data.keys()) and \
+                (self.change == True):
                 obj = context.active_object
                 oldmesh = obj.data
                 oldmeshname = obj.data.name
diff --git a/add_mesh_extra_objects/add_mesh_round_cube.py b/add_mesh_extra_objects/add_mesh_round_cube.py
index 1190be9362c133b8ee92ee264b1e60e57a84d49a..b48e9a691822131fa3442d30350461e5761cf736 100644
--- a/add_mesh_extra_objects/add_mesh_round_cube.py
+++ b/add_mesh_extra_objects/add_mesh_round_cube.py
@@ -405,7 +405,8 @@ class AddRoundCube(Operator, object_utils.AddObjectHelper):
 
         if bpy.context.mode == "OBJECT":
             if context.selected_objects != [] and context.active_object and \
-            ('Roundcube' in context.active_object.data.keys()) and (self.change == True):
+                (context.active_object.data is not None) and ('Roundcube' in context.active_object.data.keys()) and \
+                (self.change == True):
                 obj = context.active_object
                 oldmesh = obj.data
                 oldmeshname = obj.data.name
diff --git a/add_mesh_extra_objects/add_mesh_star.py b/add_mesh_extra_objects/add_mesh_star.py
index b5d515c6d795f8e41300aba58546c5db48ddf27c..2bede0814eb6a41bf5740a5b75871a8f225921b2 100644
--- a/add_mesh_extra_objects/add_mesh_star.py
+++ b/add_mesh_extra_objects/add_mesh_star.py
@@ -208,7 +208,8 @@ class AddStar(bpy.types.Operator, object_utils.AddObjectHelper):
 
         if bpy.context.mode == "OBJECT":
             if context.selected_objects != [] and context.active_object and \
-            ('Star' in context.active_object.data.keys()) and (self.change == True):
+                (context.active_object.data is not None) and ('Star' in context.active_object.data.keys()) and \
+                (self.change == True):
                 obj = context.active_object
                 oldmesh = obj.data
                 oldmeshname = obj.data.name
diff --git a/add_mesh_extra_objects/add_mesh_supertoroid.py b/add_mesh_extra_objects/add_mesh_supertoroid.py
index fabc8147d04f59ae5c6ceec17f6635bfca6c0964..8a87a289b51a556b81bff0647de7ec1fac09d19c 100644
--- a/add_mesh_extra_objects/add_mesh_supertoroid.py
+++ b/add_mesh_extra_objects/add_mesh_supertoroid.py
@@ -223,7 +223,8 @@ class add_supertoroid(bpy.types.Operator, object_utils.AddObjectHelper):
 
         if bpy.context.mode == "OBJECT":
             if context.selected_objects != [] and context.active_object and \
-            ('SuperToroid' in context.active_object.data.keys()) and (self.change == True):
+                (context.active_object.data is not None) and ('SuperToroid' in context.active_object.data.keys()) and \
+                (self.change == True):
                 obj = context.active_object
                 oldmesh = obj.data
                 oldmeshname = obj.data.name
diff --git a/add_mesh_extra_objects/add_mesh_torusknot.py b/add_mesh_extra_objects/add_mesh_torusknot.py
index 30957f7a699683f27a592d346ec9648645586a0f..39e985c307de53c63603ebffda188b46ed9a1c54 100644
--- a/add_mesh_extra_objects/add_mesh_torusknot.py
+++ b/add_mesh_extra_objects/add_mesh_torusknot.py
@@ -144,7 +144,8 @@ class AddTorusKnot(bpy.types.Operator, object_utils.AddObjectHelper):
 
         if bpy.context.mode == "OBJECT":
             if context.selected_objects != [] and context.active_object and \
-            ('TorusKnot' in context.active_object.data.keys()) and (self.change == True):
+                (context.active_object.data is not None) and ('TorusKnot' in context.active_object.data.keys()) and \
+                (self.change == True):
                 obj = context.active_object
                 oldmesh = obj.data
                 oldmeshname = obj.data.name
diff --git a/add_mesh_extra_objects/add_mesh_twisted_torus.py b/add_mesh_extra_objects/add_mesh_twisted_torus.py
index 0502a1895635da027fd0538a08b94e49f7470b35..bb3bd48385066db64bb0d897484f3e724e7da749 100644
--- a/add_mesh_extra_objects/add_mesh_twisted_torus.py
+++ b/add_mesh_extra_objects/add_mesh_twisted_torus.py
@@ -236,7 +236,8 @@ class AddTwistedTorus(bpy.types.Operator, object_utils.AddObjectHelper):
 
         if bpy.context.mode == "OBJECT":
             if context.selected_objects != [] and context.active_object and \
-            ('TwistedTorus' in context.active_object.data.keys()) and (self.change == True):
+                (context.active_object.data is not None) and ('TwistedTorus' in context.active_object.data.keys()) and \
+                (self.change == True):
                 obj = context.active_object
                 oldmesh = obj.data
                 oldmeshname = obj.data.name
diff --git a/add_mesh_geodesic_domes/third_domes_panel_271.py b/add_mesh_geodesic_domes/third_domes_panel_271.py
index 98add45f2026e11480ac70a5caf4ff8a226745de..d95de427835ab0f20722ac7f5416352fb6f3cc2f 100644
--- a/add_mesh_geodesic_domes/third_domes_panel_271.py
+++ b/add_mesh_geodesic_domes/third_domes_panel_271.py
@@ -1293,7 +1293,8 @@ class GenerateGeodesicDome(Operator, object_utils.AddObjectHelper):
         if mesh != None:
             if bpy.context.mode == "OBJECT":
                 if context.selected_objects != [] and context.active_object and \
-                ('GeodesicDome' in context.active_object.data.keys()) and (self.change == True):
+                    (context.active_object.data is not None) and \
+                    ('GeodesicDome' in context.active_object.data.keys()) and (self.change == True):
                     obj = context.active_object
                     oldmesh = obj.data
                     oldmeshname = obj.data.name