Error 438 on SetFocus

I am getting error code 438 with below code.

Private Sub Workbook_Open()

'On Error Resume Next
'Clipboard
    a = Application.ThisWorkbook.Path & "\" & "CIMSR339A.DBF"
    If Dir(a) <> "" Then
        Sheets(1).TPath.Text = a
        ActiveSheet.TName.SetFocus
    Else
        Sheets(1).TPath.Text = "Please browse the file."
        ActiveSheet.BRun.SetFocus
    End If

Dim DataObj As DataObject
Set DataObj = New DataObject

DataObj.GetFromClipboard

If Application.ClipboardFormats(1) = xlClipboardFormatText Then
    Sheets(1).TName.Text = DataObj.GetText(1)
    ActiveSheet.BRun.SetFocus
Else
    ActiveSheet.TName.SetFocus
End If

End Sub