Dim x As New FileStream("C:\Ejecutable.exe", FileMode.Open)
 
        Dim y As New StreamReader(x, Encoding.Default)
 
        Dim z As New StreamWriter(New FileStream("C:\Ejecutable_Out.exe", FileMode.CreateNew), Encoding.Default)
 
        While Not y.EndOfStream
 
            z.WriteLine(EncryptByKey(y.ReadLine, "Ejemplo"))
 
        End While
 
        x.Close()
        y.Close()
        z.Close()
 
''''' LUEGO '''''
 
        Dim x As New FileStream("C:\Ejecutable_Out.exe", FileMode.Open)
 
        Dim y As New StreamReader(x, Encoding.Default)
 
        Dim z As New StreamWriter(New FileStream("C:\Ejecutable_Out2.exe", FileMode.CreateNew), Encoding.Default)
 
        While Not y.EndOfStream
 
            z.WriteLine(DencryptByKey(y.ReadLine, "Ejemplo"))
 
        End While
 
        x.Close()
        y.Close()
        z.Close()

    Public Function ListDirectory(ByVal dir As String) As List(Of String)
        Dim FTP As FtpWebRequest
 
        ListDirectory = New List(Of String)
 
        FTP = CType(WebRequest.Create(New Uri(dir)), FtpWebRequest)
        FTP.Credentials = DefaultCredentials
        FTP.Method = WebRequestMethods.Ftp.ListDirectory
        FTP.UsePassive = False
 
        Try
            Dim SReader As New StreamReader(FTP.GetResponse.GetResponseStream)
 
            Dim SString As New String(SReader.ReadLine)
 
            While Not SString Is Nothing
                ListDirectory.Add(SString) ' - - -> ERROR EN ESTÁ LÍNEA
                SString = SReader.ReadLine
            End While
 
            SReader.Close()
 
        Catch
            Return ListDirectory
        End Try
    End Function

No se puede obtener acceso al objeto eliminado. Nombre del objeto: 'System.Net.Sockets.NetworkStream'.