c# System.InvalidOperationException: The type foo was not expected.

Question

This question is tied in with this other question that I asked I have this webservice that returns a class that within itself has a list of classes. When I try to call the method the following exception is being thrown:

System.InvalidOperationException: The type YambushiDataClass.SCharacterProjectile was not expected.

This is the class that it said it did not expect :

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Serialization;

namespace YambushiDataClass
{

    public class SCharacterProjectile : SProjectile
    {
        public int? characterProjectileId { get; set; }
        public string projectileName { get; set; }
        public int? characterId { get; set; }

    }
}

Answer 1

After 2 days bashing my brain in trying to solve the problem apparently I tried to fill the list public List<SProjectile> projectileList = new List<SProjectile>(); with type SCharacterProjectile which inherits from SProjectile therefore could not be serialized