Unity crash on my computer but not others.

I wrote a basic script for Unity in C#.

Everything was going well but during my latest tests, Unity freezed like if I launched an infinite loop. I didn't understand what was wrong so I gave my code to a friend to see if he could make it work. He got it working but after a while, there is an error about pointers. He gave it back to me and it still freeze my Unity. If I lauch the Debug, everything seem to be all right.

Do you understand what's wrong with this code? Does-it work on your computer? Should-I buy a new computer?

There is my code. To use it, include Decision and DigestiveSystem in an object. Decision's structure might seem weird but I want it to use a lot of other scripts without crashing if one is missing.

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 
 public class Decisions : MonoBehaviour
 {
     private List<string> Action;
     private List<double> Want;
     private bool exist_DS;
 
     private DigestiveSystem DS ;
 
     // Use this for initialization
     void Start ()
     {
         
         /*if (DS == null)
             Debug.Log ("null");
         else
             Debug.Log (DS.IntestinesPercentage);*/
         Action = new List<string>();
         Want = new List<double>();
         DS = null;
         exist_DS = false;
     }
 
     private void DSReady()
     {
         DS = GetComponent<DigestiveSystem> ();
     }
 
     private void DSInit()
     {
         Action.Add ("Eat");
         Action.Add ("Evacuate");
 
         Want.Add (1 - DS.StomachPercentage);
         Want.Add (DS.IntestinesPercentage);
         exist_DS = true;
     }
     // Update is called once per frame
     void Update ()
     {
         
         if (DS == null)
             Debug.Log ("null");
         else
             Debug.Log ("non-null");
         if (DS != null && exist_DS == false)
             DSInit ();
         /*if (exist_DS)
         {
             Debug.Log ("SP "+DS.StomachPercentage);
             Debug.Log ("IP "+DS.IntestinesPercentage);
         }*/
 
         int Maximum = GetWantMaxPos ();
         /*Debug.Log ("A.C "+Action.Count);
         Debug.Log ("W.C "+Want.Count);*/
         Debug.Log ("max "+Maximum);
 
         foreach(double d in Want)
         {
             Debug.Log("WANT: "+d);
         }
         /*if(Maximum!=-1)
         {
             switch (Action[Maximum])
             {
             case "eat":
                 Debug.Log("Eat");
                 GetComponent<DigestiveSystem>().Eat (1);
 
                 break;
             case "evacuate":
                 Debug.Log("Evacuate");
                 GetComponent<DigestiveSystem>().Evacuate();
 
                 break;
             }
         }*/
     }
     private int GetWantMaxPos()
     {
         int max = 0;
         for (int pos=0; pos<Want.Count; pos++)
         {
             if(Want[pos]>Want[max])
                 pos=max;
         }
         if (Want.Count == 0)
             max = -1;
         return max;
     }
 }

 using UnityEngine;
 using System.Collections;
 
 public class DigestiveSystem:MonoBehaviour
 {
     private Organ stomach;
     private Organ intestines;
     private bool IsInit;
 
     public double StomachPercentage
     {
         get{ return stomach.Percentage;}
     }
     public double IntestinesPercentage
     {
         get{ return intestines.Percentage;}
     }
     // Use this for initialization
     void Start ()
     {
         stomach = new Organ (90,100,1);
         intestines = new Organ (30,100,1);
 
         IsInit = false;
     }
     
     // Update is called once per frame
     void Update ()
     {
         if (IsInit == false)
         {
             GetComponent<Decisions>().SendMessage("DSReady");
             IsInit=true;
         }
 
         intestines.Add(stomach.Remove (Time.deltaTime));
         /*Debug.Log (Time.timeSinceLevelLoad);
         Debug.Log (stomach.Percentage);
         Debug.Log (intestines.Percentage);*/
     }
 
     public void Eat( double Qt)
     {
         stomach.Add (Qt);
     }
     public double Evacuate()
     {
         return intestines.Remove (Time.deltaTime);
     }
 }
 

 using UnityEngine;
 using System.Collections;
 
 public class Organ
 {
 
 
     private double Quantity;
     private double Max;
     private double Speed;
 
     public double Percentage
     {
         get{ return Quantity / Max;}
     }
     public Organ(double start_Quantity, double start_Max, double start_Speed)
     {
         Quantity = start_Quantity;
         Max = start_Max;
         Speed = start_Speed;
     }
 
     public void Add(double Qt)
     {
         Quantity += Qt;
     }
     public double Remove(double time)
     {
         double Qt = Speed * time;
         if (Quantity < Qt)
             Qt = Quantity;
         Quantity -= Qt;
         return Qt;
     }
 
 }