运行时错误70权限被拒绝

Question

我收到错误

  

运行时错误70权限被拒绝

尝试提供组合时。我目前的代码：

Private Sub UserForm_Initialize()
    Dim x As Long
    Dim sht As String

    sht = Sheets(1).Name
    Sheets(sht).Select
    x = 2

    Do While x <= 27
        cboUserID.AddItem Range("A" & x).Value
        x = x + 1
    Loop
End Sub