运行宏，提示错误-2147417848（80010108）

下面是具体的宏，红色部分就是报错地方。但是这个代码在其他excel就能用。这个功能是财务月报用的。其他分公司也用这个代码，但只有三、四家公司报错
大神们，请问知道这什么原因吗

Sub insert()
    Dim Message, Title, Default, rownum
    Message = "请输入需要插入的行数，行数范围从1至1000，当前默认行数为1。"
    Title = "输入行数"
    Default = "1"
    rownum = InputBox(Message, Title, Default)
    If rownum = "" Then
        End
    Else
   
    sheetname = Range("Y4")
    sheetaccess = Range("Y3")
    msg_num = "B" & Range("Y11") - 1
    If sheetaccess = "F" Then
    MsgBox "本月数据已经被保护！"
    Else
    For j = 1 To rownum
        ActiveSheet.Unprotect Password:="dtwfin0936"
        ActiveWorkbook.Unprotect Password:="dtwfin0936"
        Sheets("Backup").Visible = True
        Sheets("Backup").Select
        Range("A11:X11").Select
        Selection.Copy
        'Rows("11:11").Copy
        'ActiveWindow.ScrollColumn = 1
        
        Select Case sheetname
                Case 1
                Sheets("1").Select
                Case 2
                Sheets("2").Select
                Case 3
                Sheets("3").Select
                Case 4
                Sheets("4").Select
                Case 5
                Sheets("5").Select
                Case 6
                Sheets("6").Select
                Case 7
                Sheets("7").Select
                Case 8
                Sheets("8").Select
                Case 9
                Sheets("9").Select
                Case 10
                Sheets("10").Select
                Case 11
                Sheets("11").Select
                Case 12
                Sheets("12").Select
        End Select

        ins_num = "A" & Range("Y11")
        Range(ins_num).insert Shift:=xlDown
        Range("Y11") = Range("Y11") + 1
        ActiveSheet.Protect Password:="dtwfin0936", DrawingObjects:=True, Contents:=True, Scenarios:=True
        Sheets("Backup").Visible = False
        ActiveWorkbook.Protect Password:="dtwfin0936"
        Next j
        End If
        End If
End Sub