请教！大侠们帮忙看看这段炸开块参照的代码有误吗？

Sub tt()
On Error Resume Next
Dim i As AcadBlockReference
Dim ss As AcadSelectionSet
ThisDrawing.SelectionSets("Test").Delete
Set ss = ThisDrawing.SelectionSets.Add("Test")
Dim ft(0) As Integer, fd(0)
ft(0) = 0: fd(0) = "Insert"
ss.Select acSelectionSetAll, , , ft, fd
For Each i In ss
       MyExplode i
Next
ss.Delete
End Sub Sub MyExplode(oBlk As AcadBlockReference)
'功能：炸开嵌套块
Dim i, objs
Dim j As AcadBlockReference
       objs = oBlk.Explode
       oBlk.Delete
       For i = 0 To UBound(objs)
               If objs(i).ObjectName = "AcDbBlockReference" Then
                       Set j = objs(i)
                       MyExplode j
               End If
       Next i
End Sub