msxml“系统找不到指定的资源”

我有一个函数,它使用MSXML发布一个XML文档,尽管没有对代码做任何更改,但昨天开始失败。功能如下:

Public Function PostFile(ByVal address As String, ByVal data As Byte()) As xmldocument
    Dim xmlHTTP As New MSXML2.XMLHTTP
    Dim response As New XmlDocument

    Dim xmlDoc As New MSXML2.DOMDocument

    Try
        xmlDoc.load(data)
        xmlHTTP.open("post", address, False)
        xmlHTTP.send(xmlDoc)

        If xmlHTTP.responseXML.xml <> String.Empty Then
            response.LoadXml(xmlHTTP.responseXML.xml)
            Return response
        Else
            Dim result As String = "<NO_Response><Error>the post succeeded to " + address + " but there was no responce returned</Error><Hint>Check FireWall Settings</Hint></NO_Response>"
            response.loadxml(result)
            Return response
        End If

    Catch ex As Exception
        'Error logging code removed

    End Try
    Return Nothing
End Function

XML文档和传入的地址都是正确的-导致错误的行是 xmlHTTP.send(xmlDoc) . 我在两台不同的机器上尝试过,每次都有相同的错误,也尝试重新安装msxml3,但没有成功。

引发的异常是:

InnerException: Nothing 
Message:        "The system cannot locate the resource specified. "
Source:         "msxml3.dll"    
StackTrace:     "   at MSXML2.XMLHTTPClass.send(Object varBody)    at comms.HTTPHandler.PostFile(String address, Byte[] data) in D:\SCC\Main\Sender\Http.vb:line 42"