สอบถามปัญหา vb.net สั่ง Add header ใน excel แล้วมี error แจ้งให้ add printer

            With oSheet.PageSetup

                '.LeftHeader = "&BConfidential&B"
                '.CenterHeader = "Printed time is " & DateAdd(DateInterval.Day, 0, Now)
                '.RightHeader = "Page &P"
                '.LeftFooter = ""
                '.CenterFooter = "Page &P of &N"
                '.RightFooter = ""
                '.PrintHeadings = False
                '.PrintGridlines = False
                .PrintComments = Excel.XlPrintLocation.xlPrintNoComments
                '.PrintQuality = 600
                '.CenterHorizontally = False
                '.CenterVertically = False
                .Orientation = Excel.XlPageOrientation.xlLandscape
                '.Draft = False
                .PaperSize = Excel.XlPaperSize.xlPaperLetter
                '.FirstPageNumber = xlpxlAutomatic
                '.Order = Excel.XlOrder.xlDownThenOver
                '.BlackAndWhite = False
                '.Zoom = 100
                .PrintErrors = Excel.XlPrintErrors.xlPrintErrorsDisplayed
                .OddAndEvenPagesHeaderFooter = False
                .DifferentFirstPageHeaderFooter = False
                '.ScaleWithDocHeaderFooter = True
                .AlignMarginsHeaderFooter = True
                .EvenPage.LeftHeader.Text = ""
                .EvenPage.CenterHeader.Text = ""
                .EvenPage.RightHeader.Text = ""
                .EvenPage.LeftFooter.Text = ""
                .EvenPage.CenterFooter.Text = ""
                .EvenPage.RightFooter.Text = ""
                .FirstPage.LeftHeader.Text = ""
                .FirstPage.CenterHeader.Text = ""
                .FirstPage.RightHeader.Text = ""
                .FirstPage.LeftFooter.Text = ""
                .FirstPage.CenterFooter.Text = ""
                .FirstPage.RightFooter.Text = ""

            End With