将实体加入块，错误的原因是什么？

zzol9970

Private Sub test()
        On Error Resume Next
        Dim blockObj As AcadBlock
        Dim insertionPnt(0 To 2) As Double
        Dim circleObj As AcadCircle
        Dim center(0 To 2) As Double
        insertionPnt(0) = 0.0# : insertionPnt(1) = 0.0# : insertionPnt(2) = 0.0#
        blockObj = acadapp.ActiveDocument.Blocks.Add(insertionPnt, "CircleBlock")   ' 创建块

        center(0) = 0 : center(1) = 0 : center(2) = 0
        circleObj = acadapp.ActiveDocument.ModelSpace.AddCircle(center, 50) ' 在模型空间添加圆
        Dim objCollection(0 To 0) As Object
        objCollection(0) = circleObj                ' 创建对象集合  
        Dim retObjects As Object
        retObjects = acadapp.ActiveDocument.CopyObjects(objCollection, blockObj)  ' 拷贝对象到块中，并返回新拷贝的对象
        circleObj.Delete()
        Dim blockRefObj As AcadBlockReference
        insertionPnt(0) = 2.0# : insertionPnt(1) = 2.0# : insertionPnt(2) = 0
        blockRefObj = acadapp.ActiveDocument.ModelSpace.InsertBlock(insertionPnt, "CircleBlock", 1.0#, 1.0#, 1.0#, 0) ' 插入块到模型空间

    End Sub


retObjects = acadapp.ActiveDocument.CopyObjects(objCollection, blockObj)这一步执行未能成功，原因是什么？？？