using System;

using System.Text;

public class Program

{

    public static void Main()

    {

        string message = "Récupération du jeton de compte sur le serveur";

        Console.WriteLine(message); // Original string

        string encoded = Encoding.UTF8.GetString(Encoding.Convert(Encoding.Default, Encoding.UTF8, Encoding.Default.GetBytes(message)));

        Console.WriteLine(encoded); // Some unknown characters

        encoded = Encoding.Default.GetString(Encoding.Convert(Encoding.UTF8, Encoding.Default, Encoding.UTF8.GetBytes(encoded)));

        Console.WriteLine(encoded); // Characters seem to be lost -- not any more

    }

}