fix canvas size

operators/shape.py

@@ -95,7 +95,7 @@ class RP_OT_mirror_shape(Operator):
                 continue
 
             for mod in ob.modifiers:
-                if (mod.type == 'NODES' and mod.node_group.name == 'Symmetrize' and
+                if (mod.type == 'NODES' and mod.node_group and mod.node_group.name == 'Symmetrize' and
                         mod.get('Socket_2') in objects):
                 
                     bpy.data.objects.remove(ob)
@@ -124,7 +124,7 @@ class RP_OT_mirror_shape(Operator):
             for mod in list(flipped_object.modifiers):
                 flipped_object.modifiers.remove(mod)
 
-            # Add symmetrize modifier
+            # Add symmetrize modifier TODO add it into a resource
             mod = flipped_object.modifiers.new(name='Symmetrize', type='NODES')
             mod.node_group = bpy.data.node_groups['Symmetrize']
             mod['Socket_2'] = ob