Object Error 438 Object doesn't support this property or method

Private Sub CommandButton2_Click()
'This macro opens the SaveAs option with the defult file path "you have to set this file path below" coverts the whole sheet into .pdf file format
'And opens the .pdf to view <-- you can disable the view after covert option with lower code: OpenAfterPublish:=False




    Dim newfn As Variant
    pdfName = ActiveSheet.Range("h12")
    'copy invoice to new workbook
    ChDir "E:\bkk\mydir\dda\16-17\inv"    'This is where you set a defult file path.
    'ActiveSheet.Copy
    'newfn = "E:\bkk\mydir\dda\16-17\inv" & Range("h12").Value & ".xlsx"
    'ActiveWorkbook.SaveAs newfn fileformat: = xlopenxmlworkbook
    
    fileSaveName = Application.GetSaveAsFilename(pdfName, _
    fileFilter:="PDF Files (*.pdf), *.pdf")
    
        
    If fileSaveName <> False Then
    
        ActiveSheet.Range("a5:m44").ExportAsFixedFormat Type:=xlTypePDF, Filename:= _
        fileSaveName _
        , Quality:=xlQualityStandard, IncludeDocProperties:=True, IgnorePrintAreas _
        :=False, OpenAfterPublish:=True
         
            
    
       
     
    End If
    
    ActiveWorkbook.SaveAs "E:\bkk\mydir\dda\16-17\inv" & Sheet1("h12") & ".xlsx", FileFormat:=51
    
       
End Sub