If I delete a layer and reassign the objects to the default layer then it is no longer possible to auto-assign those objects. Create a new layer. Add some objects to the layer using select/cancel to auto-assign. Add some new objects. Exit build mode. Enter build mode Delete the new layer and reassign to the default layer. Exit build mode. Enter build mode. Create a new layer. Hide the new layer so you can tell which objects are in it. Make sure auto-add is enabled (the + sign in the layer HUD should show) Select/cancel a objects which were never on a layer and it should disappear once in the new layer. Select/cancel objects which were formerly on the deleted layer. Nothing happens if it wasn't assigned.