Creating a Block With an Attribute, Why Does One Work, But Not The Other

I want to create a block that includes a polyline (in a rounded triangle shape) and an attribute.
In this first example (which I found online, I can successfully create the block if I use a circle.

` Public Sub CreateDeltaNoteBlock2(ByVal dwg_scale As Double)
"Get the current database and start a transaction
Dim podDWG As Document = Application.DocumentManager.MdiActiveDocument
Dim podDB As Database = podDWG.Database

    Using acTrans As Transaction = podDB.TransactionManager.StartTransaction()
        "Open the Block table for read
        Dim acBlkTbl As BlockTable
        acBlkTbl = acTrans.GetObject(podDB.BlockTableId, OpenMode.ForRead)

        If Not acBlkTbl.Has("Delta_Note") Then
            Using acBlkTblRec As New BlockTableRecord
                acBlkTblRec.Name = "Delta_Note"

                "Set the insertion point for the block
                acBlkTblRec.Origin = New Point3d(0, 0, 0)

                "Add a circle to the block
                Using acCirc As New Circle
                    acCirc.Center = New Point3d(0, 0, 0)
                    acCirc.Radius = 6 * dwg_scale

                    acBlkTblRec.AppendEntity(acCirc)

                    "Add an attribute definition to the block
                    Using acAttDef As New AttributeDefinition
                        acAttDef.Position = New Point3d(0, 0, 0)
                        acAttDef.Verifiable = True
                        acAttDef.Prompt = "Enter Delta Number: "
                        acAttDef.Tag = "DeltaNote"
                        acAttDef.TextString = ""
                        acAttDef.Height = 1
                        acAttDef.Justify = AttachmentPoint.MiddleCenter
                        acBlkTblRec.AppendEntity(acAttDef)

                        acBlkTbl.UpgradeOpen()
                        acBlkTbl.Add(acBlkTblRec)
                        acTrans.AddNewlyCreatedDBObject(acBlkTblRec, True)
                    End Using
                End Using
            End Using
        End If

        "Save the new object to the database
        acTrans.Commit()

    End Using
End Sub'

But when I use the same code and I replace the circle with a polyline. It skips the "Using acAttDef As New AttributeDefinition" section.
` Public Sub CreateDeltaNoteBlock2(ByVal dwg_scale As Double)
"Get the current database and start a transaction
Dim podDWG As Document = Application.DocumentManager.MdiActiveDocument
Dim podDB As Database = podDWG.Database

    Using acTrans As Transaction = podDB.TransactionManager.StartTransaction()
        "Open the Block table for read
        Dim acBlkTbl As BlockTable
        acBlkTbl = acTrans.GetObject(podDB.BlockTableId, OpenMode.ForRead)

        If Not acBlkTbl.Has("Delta_Note") Then
            Using acBlkTblRec As New BlockTableRecord
                acBlkTblRec.Name = "Delta_Note"

                "Set the insertion point for the block
                acBlkTblRec.Origin = New Point3d(0, 0, 0)

                Dim centerPoint As Point2d = New Point2d(0, 0)
                Dim distFromCenter As Double = 4.944
                Dim delta_pt1 As Point2d = PolarPoints2D(centerPoint, DegreesToRadians(201.0), (distFromCenter * dwg_scale))
                Dim delta_pt2 As Point2d = PolarPoints2D(centerPoint, DegreesToRadians(219.0), (distFromCenter * dwg_scale))
                Dim delta_pt3 As Point2d = PolarPoints2D(centerPoint, DegreesToRadians(321.0), (distFromCenter * dwg_scale))
                Dim delta_pt4 As Point2d = PolarPoints2D(centerPoint, DegreesToRadians(339.0), (distFromCenter * dwg_scale))
                Dim delta_pt5 As Point2d = PolarPoints2D(centerPoint, DegreesToRadians(81.0), (distFromCenter * dwg_scale))
                Dim delta_pt6 As Point2d = PolarPoints2D(centerPoint, DegreesToRadians(99.0), (distFromCenter * dwg_scale))
               " Add a circle to the block
                "Using acCirc As New Circle
                "acCirc.Center = New Point3d(0, 0, 0)
                "acCirc.Radius = 6 * dwg_scale

                "Create the polyline
                Using deltaPoly As New Polyline
                    deltaPoly.SetDatabaseDefaults()
                    deltaPoly.AddVertexAt(0, delta_pt1, 0, 0, 0)
                    deltaPoly.AddVertexAt(1, delta_pt2, 0, 0, 0)
                    deltaPoly.AddVertexAt(2, delta_pt3, 0, 0, 0)
                    deltaPoly.AddVertexAt(3, delta_pt4, 0, 0, 0)
                    deltaPoly.AddVertexAt(4, delta_pt5, 0, 0, 0)
                    deltaPoly.AddVertexAt(5, delta_pt6, 0, 0, 0)
                    deltaPoly.Closed = True

                    "Sets the bulge at index 0, 2, and 4
                    deltaPoly.SetBulgeAt(0, (Math.Tan((120 / 4) * (Math.PI / 180))))
                    deltaPoly.SetBulgeAt(2, (Math.Tan((120 / 4) * (Math.PI / 180))))
                    deltaPoly.SetBulgeAt(4, (Math.Tan((120 / 4) * (Math.PI / 180))))

                    acBlkTblRec.AppendEntity(deltaPoly)

                    "Add an attribute definition to the block
                    Using acAttDef As New AttributeDefinition
                        acAttDef.Position = New Point3d(0, 0, 0)
                        acAttDef.Verifiable = True
                        acAttDef.Prompt = "Enter Delta Number: "
                        acAttDef.Tag = "DeltaNote"
                        acAttDef.TextString = ""
                        acAttDef.Height = 1
                        acAttDef.Justify = AttachmentPoint.MiddleCenter
                        acBlkTblRec.AppendEntity(acAttDef)

                        acBlkTbl.UpgradeOpen()
                        acBlkTbl.Add(acBlkTblRec)
                        acTrans.AddNewlyCreatedDBObject(acBlkTblRec, True)
                    End Using
                End Using
            End Using
        End If

       " Save the new object to the database
        acTrans.Commit()

    End Using
End Sub`

A pic of the error is attached, though I've created polylines before without issue.