接受会议时的运行时错误438

Question

当我想接受会议请求时，我得到运行时错误438 - ＆gt;运行调试后，错误行是：

If TypeOf objItem Is Outlook.MailItem And objItem.BodyFormat = olFormatHTML Then

Sub AddBanner()

' version: 1.0
'=================================================================

    Dim BannerURL As String
    Dim BannerTargetURL As String
    Dim BannerWidth As Integer
    Dim BannerHeight As Integer
    Dim PromptSend As Boolean

    '==================BEGIN MODIFY ================================================
    BannerURL = "http://domain.tld/email_signature/banner.png"
    BannerTargetURL = ""
    BannerWidth = 361
    BannerHeight = 61
    PromptSend = False
    '==================END MODIFY ==================================================

    If TypeOf objItem Is Outlook.MailItem And objItem.BodyFormat = olFormatHTML Then
        If PromptSend = True Then
            Dim Result As VbMsgBoxResult
            Result = MsgBox("Do you want to include your banner to this message?", _
                        vbQuestion + vbYesNo, "Add Banner")
            If Result = vbNo Then
                Exit Sub
            End If
        End If

        Dim strTopHTML As String
        strTopHTML = "<p><a href=""" & BannerTargetURL & """><img width=""" _
                        & BannerWidth & """ height=""" & BannerHeight & _
                        """ src=""" & BannerURL & """ /></a></p>"
        strHTMLBody = objItem.HTMLBody
        intTagStart = InStr(1, strHTMLBody, "<body", vbTextCompare)
        intTagEnd = InStr(intTagStart + 5, strHTMLBody, ">")
        strBodyTag = Mid(strHTMLBody, intTagStart, intTagEnd - intTagStart + 1)
        objItem.HTMLBody = Replace(strHTMLBody, strBodyTag, strBodyTag & strTopHTML)

    End If

End Sub