ArgumentOutOfRangeException: Argument is out of range. Parameter name: index System.

i am trying to run my game but everytime i get this exception.

My Script :

using UnityEngine; using System.Collections; using System.Collections.Generic;

public class GameManager : MonoBehaviour { public List Characters = new List (); bool ShowCharWheel; public int SelectedCharacter; int LastCharacter; public static GameManager Instance;

 void Awake()
 {
     Instance = this;
     foreach(Character c in Characters) 
     {
         c.Instance = Instantiate(c.PlayerPrefab,c.HomeSpawn.position, c.HomeSpawn.rotation) as GameObject;
     }
     ChangeCharacter (Characters [PlayerPrefs.GetInt("SelectedChar")]);
 }

 // Use this for initialization
 void Start ()
 {
             
 }

 // Update is called once per frame
 void Update () {
     if(Input.GetKey(KeyCode.C)){
         ShowCharWheel = true;
         Screen.showCursor = true;
     }
     else{
         ShowCharWheel = false;
         Screen.showCursor = false;
     }

 }
 void ChangeCharacter(Character c)
 {
     LastCharacter = SelectedCharacter;
     SelectedCharacter = Characters.IndexOf (c);
     Characters[LastCharacter].Instance.GetComponent<PlayerController>().CanPlay = false;
     Characters[SelectedCharacter].Instance.GetComponent<PlayerController>().CanPlay = true;
     Camera.main.GetComponent<SmoothFollow>().target = Characters[SelectedCharacter].Instance.transform;
     PlayerPrefs.SetInt ("SelectedChar", SelectedCharacter);
 }
 void OnGUI()
 {
     if (ShowCharWheel)
     {
         GUILayout.BeginArea(new Rect(Screen.width - 64, Screen.height - 192,62,192),GUIContent.none,"box");
         foreach(Character c in Characters)
         {
             if (GUILayout.Button(c.Icon,GUILayout.Width(64),GUILayout.Height (64)))
             {
                 ChangeCharacter(c);
             }
         }
         GUILayout.EndArea();
     }
 }

}

[System.Serializable] public class Character { public string Name; public Texture2D Icon; public GameObject PlayerPrefab; public GameObject Instance; public Transform HomeSpawn;

}