求助：以下代码运行后创建布局，但跳出错误信息

zhu1983

通过运行以下代码创建布局，但当切换到该布局时，跳出错误信息： “内部错误：！dbsymblk.cpp@588:eNullObjectId”  。
是何原因？如何解决？望高人指点！
Public Sub CreatLayouts(ByVal VPNo As Double)
        Dim db As Database = HostApplicationServices.WorkingDatabase
        Dim acLayoutName As String = "VP" & VPNo
        Using Trans As Transaction = db.TransactionManager.StartTransaction()
            Dim acLayout As New Layout
            acLayout.LayoutName = acLayoutName
            Dim acLayoutDic As DBDictionary = Trans.GetObject(db.LayoutDictionaryId, OpenMode.ForWrite)
            acLayoutDic.SetAt(acLayoutName, acLayout)
            Trans.AddNewlyCreatedDBObject(acLayout, True)
            Trans.Commit()
        End Using
    End Sub