While fixing my UML I get this error (#1579)

System.ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection.

Parameter name: index

at System.ThrowHelper.ThrowArgumentOutOfRangeException(ExceptionArgument argument, ExceptionResource resource)

at SoftwareIdeasModeler.Core.DiagramItems.Concrete.ConcreteRelation.GetLineSegment(Int32 index)

at SoftwareIdeasModeler.Core.DiagramItems.Concrete.ConcreteRelation.GetLineForControlPoint(Int32 pointIndex)

at SoftwareIdeasModeler.Core.DiagramItems.Concrete.ConcreteRelation.GetLineForPoint(Int32 pointIndex)

at SoftwareIdeasModeler.Core.DiagramItems.Concrete.ConcreteRelation.DrawPointsAndSubLines(DiagramDrawer drawer, DrawingParameters param)

at SoftwareIdeasModeler.Core.DiagramItems.Concrete.ConcreteRelation.DrawRelationLine(DiagramDrawer drawer, DrawingParameters param)

at SoftwareIdeasModeler.Core.DiagramItems.Uml.ConcreteUmlContainment.DrawElement(DiagramDrawer drawer, DrawingParameters param)

at SoftwareIdeasModeler.Core.Projecting.ConcreteDiagramElement.Draw(DiagramDrawer drawer, DrawingParameters param)

at SoftwareIdeasModeler.Core.DiagramRendering.DiagramDrawer.Draw(DiagramLayer layer, IConcreteDiagramElement item)

at SoftwareIdeasModeler.Core.DiagramRendering.DiagramDrawer.Draw(DiagramLayer layer, Rectangle clipArea)

at SoftwareIdeasModeler.Core.DiagramRendering.DiagramDrawer.Draw(Diagram diagram, Rectangle drawBounds)

at SoftwareIdeasModeler.SimDiagramControl.canvas_Paint(Object sender, PaintEventArgs e)

at System.Windows.Forms.Control.OnPaint(PaintEventArgs e)

at System.Windows.Forms.Control.PaintWithErrorHandling(PaintEventArgs e, Int16 layer)

at System.Windows.Forms.Control.WmPaint(Message& m)

at System.Windows.Forms.Control.WndProc(Message& m)

at System.Windows.Forms.ScrollableControl.WndProc(Message& m)

at System.Windows.Forms.ContainerControl.WndProc(Message& m)

at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)

at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)

at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

OF=SoftwareIdeasModeler.MainForm

LastCmd=SoftwareIdeas.Common.Commands.CombinedCommand