Cannot change Lens Flare Ignore Layers list

When ever I try to modify the list I get this:

Using a SerializedProperty after the object has been deleted is not possible. UnityEditor.EditorGUI:SetLayerMaskValueDelegate(Object, String[], Int32)

Now this is just me adding a new game object directional light and adding a lens flare component. It is sitting in the root of the hierarchy with no scripts attached to it.

If I add one with the defaults, it works but as soon as I try to modify it BOOM...

This appears to be fixed in the latest version of Unity.