diff --git a/cura/ConvexHullDecorator.py b/cura/ConvexHullDecorator.py
old mode 100644
new mode 100755
index da72ffdbe3..404342fb78
--- a/cura/ConvexHullDecorator.py
+++ b/cura/ConvexHullDecorator.py
@@ -59,7 +59,8 @@ class ConvexHullDecorator(SceneNodeDecorator):
         hull = self._compute2DConvexHull()
 
         if self._global_stack and self._node:
-            if self._global_stack.getProperty("print_sequence", "value") == "one_at_a_time" and not self._node.getParent().callDecoration("isGroup"):
+            # Parent can be None if node is just loaded.
+            if self._global_stack.getProperty("print_sequence", "value") == "one_at_a_time" and (self._node.getParent() is None or not self._node.getParent().callDecoration("isGroup")):
                 hull = hull.getMinkowskiHull(Polygon(numpy.array(self._global_stack.getProperty("machine_head_polygon", "value"), numpy.float32)))
                 hull = self._add2DAdhesionMargin(hull)
         return hull
@@ -79,7 +80,7 @@ class ConvexHullDecorator(SceneNodeDecorator):
             return None
 
         if self._global_stack:
-            if self._global_stack.getProperty("print_sequence", "value") == "one_at_a_time" and not self._node.getParent().callDecoration("isGroup"):
+            if self._global_stack.getProperty("print_sequence", "value") == "one_at_a_time" and (self._node.getParent() is None or not self._node.getParent().callDecoration("isGroup")):
                 head_with_fans = self._compute2DConvexHeadMin()
                 head_with_fans_with_adhesion_margin = self._add2DAdhesionMargin(head_with_fans)
                 return head_with_fans_with_adhesion_margin
@@ -93,8 +94,7 @@ class ConvexHullDecorator(SceneNodeDecorator):
             return None
 
         if self._global_stack:
-            if self._global_stack.getProperty("print_sequence", "value") == "one_at_a_time" and not self._node.getParent().callDecoration("isGroup"):
-
+            if self._global_stack.getProperty("print_sequence", "value") == "one_at_a_time" and (self._node.getParent() is None or not self._node.getParent().callDecoration("isGroup")):
                 # Printing one at a time and it's not an object in a group
                 return self._compute2DConvexHull()
         return None
@@ -335,4 +335,4 @@ class ConvexHullDecorator(SceneNodeDecorator):
     ##  Settings that change the convex hull.
     #
     #   If these settings change, the convex hull should be recalculated.
-    _influencing_settings = {"xy_offset", "mold_enabled", "mold_width"}
\ No newline at end of file
+    _influencing_settings = {"xy_offset", "mold_enabled", "mold_width"}
diff --git a/cura/ShapeArray.py b/cura/ShapeArray.py
index 534fa78e4d..95d0201c38 100755
--- a/cura/ShapeArray.py
+++ b/cura/ShapeArray.py
@@ -43,8 +43,10 @@ class ShapeArray:
         transform_x = transform._data[0][3]
         transform_y = transform._data[2][3]
         hull_verts = node.callDecoration("getConvexHull")
+        # For one_at_a_time printing you need the convex hull head.
+        hull_head_verts = node.callDecoration("getConvexHullHead") or hull_verts
 
-        offset_verts = hull_verts.getMinkowskiHull(Polygon.approximatedCircle(min_offset))
+        offset_verts = hull_head_verts.getMinkowskiHull(Polygon.approximatedCircle(min_offset))
         offset_points = copy.deepcopy(offset_verts._points)  # x, y
         offset_points[:, 0] = numpy.add(offset_points[:, 0], -transform_x)
         offset_points[:, 1] = numpy.add(offset_points[:, 1], -transform_y)