Deserylization from the collection. C#

[rosemadder]

List<Person> parts = new List<Person>();
        XmlSerializer xs = new XmlSerializer(typeof(List<Person>));
        //Код десериализации ломает программу
        if (File.Exists("person.xml")){

        using (FileStream fs = new FileStream("person.xml", FileMode.OpenOrCreate))
        {
            List<Person> newParts = (List<Person>)xs.Deserialize(fs);
            Console.WriteLine("Объект десериализован");}
        }while (true)
        {
            Console.WriteLine("Введите команду:");
            string com = Console.ReadLine();
            if (com.ToLower() == "exit")
            {
                using (FileStream fs = new FileStream("person.xml", FileMode.OpenOrCreate))
                {
                    xs.Serialize(fs, parts);
                   // Console.WriteLine("Объект сериализован");
                }
                return;
            }
            if (com.ToLower() == "add")
            {
                 string name;
                 Console.WriteLine("Name?");
                 name = Console.ReadLine();
                 Person p = new Person(name);
                 parts.Add(p);
            }
            if (com.ToLower() != "add")
            {
                Console.WriteLine("Доступные команды:");
                Console.WriteLine("\tadd создать запись сотрудника");
                Console.WriteLine("\texit Выйти и сохранить данные");
                Console.ReadKey();
                continue;
            }

       }

     }
}  
  [Serializable]
   public class Person
   {
       public string Name { get; set; }
       public Person()
       { }
       public Person(string name)
       {
           Name = name;
       }
   }
}

Hello, I'm doing a database. The menu is console. I'm adding a staff member to the collaboration parts. With "exit" on the xml

in person.xml. Everything's going great. But when I put in a code to get this file checked in on the launch, and his desserization broken my program. What's the reason?

[Bogopo]

Check if you have a file before desservation:

  if (File.Exists("person.xml"))
  using (FileStream fs = new FileStream("person.xml", FileMode.OpenOrCreate))