底层连接已关闭。服务器提交了协议违规vb.net

Question

我需要帮助，我似乎无法找到解决问题的方法。

我正在尝试在FTP服务器中创建一个目录：

Dim request As FtpWebRequest = FtpWebRequest.Create("ftp:\\*******")
        Dim creds As NetworkCredential = New NetworkCredential("****", "*****")
        request.Credentials = creds
        request.KeepAlive = True
        request.EnableSsl = True
        request.UsePassive = True

        request.Timeout = 10000000
        request.ReadWriteTimeout = 10000000
        ServicePointManager.ServerCertificateValidationCallback = New System.Net.Security.RemoteCertificateValidationCallback(AddressOf customCertValidation)

        Dim resp As FtpWebResponse = Nothing
        request.Method = WebRequestMethods.Ftp.ListDirectoryDetails

        Using resp
            resp = request.GetResponse()
            Dim sr As StreamReader = New StreamReader(resp.GetResponseStream(), System.Text.Encoding.ASCII)
            Dim s As String = sr.ReadToEnd()
            If Not s.Contains("newfolder") Then

                request = FtpWebRequest.Create("ftp:\\********")
                request.Credentials = creds
                request.Method = WebRequestMethods.Ftp.MakeDirectory
                resp = request.GetResponse()
                Console.WriteLine(resp.StatusCode & "Created")
            Else
                Console.WriteLine("Directory already exists")
            End If
        End Using
    Catch ex As Exception
        Console.WriteLine(ex.ToString)
    End Try

customCertValidation函数

Function customCertValidation(ByVal sender As Object,
                                            ByVal cert As X509Certificate,
                                            ByVal chain As X509Chain,
                                            ByVal errors As SslPolicyErrors) As Boolean
    Return True
End Function

我收到以下错误：

我已尝试过网络上的所有内容，但似乎没有任何效果，有人可以告诉我出了什么问题。 谢谢