Code

            Diagram d = new Diagram();
            TableNode a1, a2;
            d.Nodes.Add(a1 = new TableNode(d));
            d.Nodes.Add(a2 = new TableNode(d));
            d.Links.Add(new DiagramLink(d, a1, a2));
            d.Links.Add(new DiagramLink(d, a1, a2));
            d.Links.Add(new DiagramLink(d, a2, a1));
            d.Links.Add(new DiagramLink(d, a2, a1));

            LayeredLayout ll = new LayeredLayout
            {
                EnforceLinkFlow = true,
                StraightenLongLinks = true,
            };

            ll.Arrange(d); 

Code

   at System.ThrowHelper.ThrowKeyNotFoundException()
   at System.Collections.Generic.Dictionary`2.get_Item(TKey key)
   at MindFusion.Layout.x348b8deb5aa85ce7.x210b394f42751fdc()
   at MindFusion.Layout.x348b8deb5aa85ce7.xb7874248b0c0bc2d(x5e63d74830b5db57 x8e7bfcccb55aaf8f, xae117168b0e0c39f x8d3f74e5f925679c, x78e3ce9dc43283f0 x22bfd1664c623dc4)
   at MindFusion.Diagramming.Silverlight.Layout.LayeredLayout.Arrange(Diagram diagram, DiagramItemCollection items)
   at MindFusion.Diagramming.Silverlight.Layout.Layout.Arrange(Diagram diagram)