Error in point constructor

i m using this as link template but when i load my model i get this error

  this.Go(go.Link,  // the whole link panel
    {isTreeLink: false,
      isLayoutPositioned: false, selectable: true, selectionAdornmentTemplate: linkSelectionAdornmentTemplate },
    { relinkableFrom: true, relinkableTo: true, reshapable: true },
      // routing: go.Link.Orthogonal,
      curve: go.Link.Bezier,
      toShortLength: 4
    new go.Binding("fromEndSegmentLength")
    ,new go.Binding("toEndSegmentLength"),
    // new go.Binding("points").makeTwoWay(),
    this.Go(go.Shape,  // the link path shape
      { fill: "#0080ff", isPanelMain: true, strokeWidth: 1, stroke: "#0080ff" }),
    this.Go(go.Shape,  // the arrowhead
      { fill: "#0080ff", toArrow: "Standard", stroke: null })

When I use your template, unmodified except for removing the selectionAdornmentTemplate which I cannot guess at, the template works well.

Could you please tell us how to reproduce the exception?