Ошибка сериализацией листа обьектов - C#

An unhandled exception of type 'System.InvalidOperationException' occurred in System.Xml.dll
 
Additional information: There was an error reflecting type 'System.Collections.Generic.List`1[cursova6.Client]'.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Reflection;
namespace cursova6
{
    [Serializable]
   public class Client
    {
 
        public string Name{get;set;}
        public string Surname { get; set; }
        public int Npassport { get; set; }
        public string Adres { get; set; }
        public int Telefon { get; set; }
        public int Nombank { get; set; }
        public string Tipneruh { get; set; }
        public int Vcena { get; set; }
        public List<Realty> Neruh { get; set; }
        public Client(string name, string surname, int npassport, string adres, int telefon, int nombank, string tipneruh, int vcena)
        {
            Name = name;
            Surname = surname;
            Npassport = npassport;
            Adres = adres;
            Telefon = telefon;
            Nombank = nombank;
            Tipneruh = tipneruh;
            Vcena = vcena;
            Neruh = new List<Realty>();
        }
        public Client()
        {
 
        }
        public string Description()
        {
            var sb = new StringBuilder();
            PropertyInfo[] properties = this.GetType().GetProperties();
            foreach (PropertyInfo propertyInfo in properties)
            {
                sb.Append(propertyInfo.GetValue(this));
                sb.Append(" ");
            }
 
            return sb.ToString();
        }
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Reflection;
namespace cursova6
{
 
    public class Realty
    {
        public string Name { get; set; }
        public double Vartist { get; set; }
        public string Mrozt { get; set; }
        public Firstvlas Popvlas{get; set;}
 
        public Realty(string name, double vartist, string mrozt,ref Firstvlas popvlas)
        {
            Name = name;
            Vartist = vartist;
            Mrozt = mrozt;
            Popvlas = popvlas;
        }
 
        public string Description()
        {
            var sb = new StringBuilder();
            PropertyInfo[] properties = this.GetType().GetProperties();
            foreach (PropertyInfo propertyInfo in properties)
            {
                sb.Append(propertyInfo.GetValue(this));
                sb.Append(" ");
            }
 
            return sb.ToString();
        }
    }
}

        public static void serilaze<T>(T vector, string filename)
        {
            XmlSerializer writer = new XmlSerializer(vector.GetType());
            var path = filename;
            FileStream file = new FileStream(path, FileMode.Truncate);
            writer.Serialize(file, vector);
            file.Close();
        }
 
        public static T desirelize<T>(string filename)
        {
            System.Xml.Serialization.XmlSerializer reader =
                new System.Xml.Serialization.XmlSerializer(typeof(T));
            System.IO.StreamReader file = new System.IO.StreamReader(
                filename);
            T overview;
            overview = (T)reader.Deserialize(file);
            file.Close();
            return overview;
        }

XmlSerializer writer = new XmlSerializer(vector.GetType());