what am I doing wrong

I have a contoller script that my playerstats derives from. I want to put it on my main
camera so that when you hit play the stats of each character here is what I am
working with:

using UnityEngine;
using System.Collections;

public class Controller : MonoBehaviour {

	 public PlayerStats _jake;




    void Start(){

    	_jake.level = 3;  
    	_jake.STR = 50;
        _jake.DEX = 55;
        _jake.DEF = 50;
        _jake.vital = 100;
        _jake.Magic = 60;
        _jake.luck = 45;
        _jake.Speed = 56;
        _jake.Agility = 46;
        _jake.exp.Cur = 0;

note:Jake is just one of the characters that need this script there are four more party members too.
here is PlayerStats:

public class PlayerStats : Controller {

	public int level;
	public string name;
	public Stat Hp = new Stat();
	public Stat Mp = new Stat();
	public int STR;
	public int DEX;
	public int DEF;
	public int vital;
	public int Magic;
	public int luck;
	public int Speed;
	public int Agility;
	public int melee;
	public int ranged;
	public int MagA;
	public int MagD;
	public float active;
	public Stat exp = new Stat();
	public void addexp(int ex){
		exp.Cur += ex;
		while(exp.Cur >= exp.Max && level < 99){
			exp.Cur -= exp.Max;
			exp.Max = level *(level+1)* 500;
	void upstats(){
		melee =(level*7)+STR;
		ranged =(level*7)+DEX;
		DEF =(level*2)+ Agility;
		MagA =(level*7)+ Magic;
		MagD =(level*2)+ luck;
		active =20+((Speed * level)/1500);
		Hp.Max =((level * 5)+ vital)*10;
		Hp.Cur = Hp.Max;
		Mp.Max =((level * 5)+ Magic)*10;
		Mp.Cur = Mp.Max;
	    public class Stat{
		public int Cur;
		public int Max;
		public PlayerStats(int level,string name,int STR,int DEX,int DEF,int vital,int Magic,int luck,int speed,int Agility,int exp){
		this.level = 1;
		this.name = name;
		this.STR = STR;
		this.DEF = DEF;
		this.vital = vital;
		this.Magic = Magic;
		this.luck = luck;
		this.Speed = speed;
		this.Agility = Agility;


this script runs from the Project tab. and the controller script attaches to camera
because it is for my characters all 5 of them who are in the party. I also am getting
an error that says stack overflow extintion

If I am understanding what it is you are wanting to do, you need to add [System.Serializable] above your PlayerStats class.