Saveing and Loading Problem

so i need to save a custom object and load it whenever and it gives me errors i have no idea how to fix. it gives me the error: IOException: Sharing violation on path C:\Users(-)\AppData\LocalLow\DefaultCompany\first 2d unity project\gamedata1.us /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.IO/FileStream.cs 320

and error: SerializationException: Unexpected binary element: 255 /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Runtime.Serialization.Formatters.Binary/ObjectReader.cs 254
the code: script1:

 using UnityEngine;
 using System.Collections;
 using UnityEngine.UI;
 using System;
 
 public class checkprog1 : MonoBehaviour {
     public Text progdisp1;
     public Text progdisp2;
     public Text progdisp3;
     private progress.savedata a;
     private progress.savedata b;
     private progress.savedata c;
     // Use this for initialization
     void Start () {
       
     }
     void progdisp(Text a, progress.savedata b)
     {
         if (b == null)
         {
             a.text = "No Save  Present";
         }
         else
         {
             a.text = "Level " + b.farthestlvl().ToString();
         }
     }
   
     // Update is called once per frame
     void Update () {
       
         a = utilities.sLoad("1");
         b = utilities.sLoad("2");
         c = utilities.sLoad("3");
 
         progdisp(progdisp1, a);
         progdisp(progdisp2, b);
         progdisp(progdisp3, c);
     }
 }
 

script2:

 using UnityEngine;
 using System.Collections;
 using UnityEngine.UI;
 using UnityEngine.EventSystems;
 using UnityEngine.SceneManagement;
 using System.Collections.Generic;
 using System.Runtime.Serialization.Formatters.Binary;
 using System.IO;
 using System;
 
 public class utilities : MonoBehaviour {
     public static bool donelvls;
     public static GameObject credits;
     public static GameObject levelselect;
     public static GameObject options;
     public static GameObject quit;
     public static GameObject secret;
     public static GameObject selectselect;
     public static GameObject save;
     public static int bfrag;
     public static string bas;
     public static BinaryFormatter binf;
     private void Awake()
     {
         Environment.SetEnvironmentVariable("MONO_REFLECTION_SERIALIZER", "yes");
     }
     public void Save(progress.savedata a, string b)
     {
         delete(b);
         FileStream file = File.Create(Application.persistentDataPath + "/gamedata" + b + ".usd");
         binf.Serialize(file, a);
         file.Close();
     }
     public progress.savedata Load(string b)
     {
         if (File.Exists(Application.persistentDataPath + "/gamedata" + b + ".usd"))
         {
             FileStream file = File.Open(Application.persistentDataPath + "/gamedata" + b + ".usd", FileMode.Open);
             progress.savedata c = (progress.savedata)binf.Deserialize(file);
             file.Close();
             return c;
         }
         else
         {
             return null;
         }
     }
     public static progress.savedata sLoad(string b)
     {
         if (File.Exists(Application.persistentDataPath + "/gamedata" + b + ".usd"))
         {
             FileStream file = File.Open(Application.persistentDataPath + "/gamedata" + b + ".usd", FileMode.Open);
             progress.savedata c = (progress.savedata)binf.Deserialize(file);
             file.Close();
             return c;
         }
         else
         {
             return null;
         }
     }
     public void fullload(string b)
     {
         if(Load(b) != null)
         {
             progress.gamedata = Load(b);
         }
         else
         {
             progress.gamedata = new progress.savedata();
         }
     }
     public void load1()
     {
         fullload("1");
     }
     public void load2()
     {
         fullload("2");
     }
     public void load3()
     {
         fullload("3");
     }
     public void save1()
     {
         Save(progress.gamedata, "1");
     }
     public void save2()
     {
         Save(progress.gamedata, "2");
     }
     public void save3()
     {
         Save(progress.gamedata, "3");
     }
     public void delete1()
     {
         delete("1");
     }
     public void delete2()
     {
         delete("2");
     }
     public void delete3()
     {
         delete("3");
     }
     public void delete(string b)
     {
         if (File.Exists(Application.persistentDataPath + "/gamedata" + b + ".usd"))
             File.Delete(Application.persistentDataPath + "/gamedata" + b + ".usd");
       
     }

script3:

 using UnityEngine;
 using System.Collections;
 using System;
 
 public class progress : MonoBehaviour
 {
   
     public static savedata gamedata;
 
     // Use this for initialization
     void Start()
     {
         gamedata = new savedata();
         DontDestroyOnLoad(transform.gameObject);
     }
     // Update is called once per frame
     void Update()
     {
         if (savedata.l1.b1 && savedata.l1.b2 && savedata.l1.b3)
         {
             savedata.l1.b4 = true;
         }
         else
         {
             savedata.l1.b4 = false;
         }
         if (savedata.l2.b1 && savedata.l2.b2 && savedata.l2.b3)
         {
             savedata.l2.b4 = true;
         }
         else
         {
             savedata.l2.b4 = false;
         }
         if (savedata.l3.b1 && savedata.l3.b2 && savedata.l3.b3)
         {
             savedata.l3.b4 = true;
         }
         else
         {
             savedata.l3.b4 = false;
         }
         if (savedata.l4.b1 && savedata.l4.b2 && savedata.l4.b3)
         {
             savedata.l4.b4 = true;
         }
         else
         {
             savedata.l4.b4 = false;
         }
         if (savedata.l5.b1 && savedata.l5.b2 && savedata.l5.b3)
         {
             savedata.l5.b4 = true;
         }
         else
         {
             savedata.l5.b4 = false;
         }
         if (savedata.l6.b1 && savedata.l6.b2 && savedata.l6.b3)
         {
             savedata.l6.b4 = true;
         }
         else
         {
             savedata.l6.b4 = false;
         }
         if (savedata.l7.b1 && savedata.l7.b2 && savedata.l7.b3)
         {
             savedata.l7.b4 = true;
         }
         else
         {
             savedata.l7.b4 = false;
         }
         if (savedata.l8.b1 && savedata.l8.b2 && savedata.l8.b3)
         {
             savedata.l8.b4 = true;
         }
         else
         {
             savedata.l8.b4 = false;
         }
         if (savedata.l9.b1 && savedata.l9.b2 && savedata.l9.b3)
         {
             savedata.l9.b4 = true;
         }
         else
         {
             savedata.l9.b4 = false;
         }
         if (savedata.l10.b1 && savedata.l10.b2 && savedata.l10.b3)
         {
             savedata.l10.b4 = true;
         }
         else
         {
             savedata.l10.b4 = false;
         }
         if (savedata.l11.b1 && savedata.l11.b2 && savedata.l11.b3)
         {
             savedata.l11.b4 = true;
         }
         else
         {
             savedata.l11.b4 = false;
         }
         if (savedata.l12.b1 && savedata.l12.b2 && savedata.l12.b3)
         {
             savedata.l12.b4 = true;
         }
         else
         {
             savedata.l12.b4 = false;
         }
         if (savedata.l13.b1 && savedata.l13.b2 && savedata.l13.b3)
         {
             savedata.l13.b4 = true;
         }
         else
         {
             savedata.l13.b4 = false;
         }
         if (savedata.l14.b1 && savedata.l14.b2 && savedata.l14.b3)
         {
             savedata.l14.b4 = true;
         }
         else
         {
             savedata.l14.b4 = false;
         }
         if (savedata.l15.b1 && savedata.l15.b2 && savedata.l15.b3)
         {
             savedata.l15.b4 = true;
         }
         else
         {
             savedata.l15.b4 = false;
         }
         if (savedata.l16.b1 && savedata.l16.b2 && savedata.l16.b3)
         {
             savedata.l16.b4 = true;
         }
         else
         {
             savedata.l16.b4 = false;
         }
         if (savedata.l17.b1 && savedata.l17.b2 && savedata.l17.b3)
         {
             savedata.l17.b4 = true;
         }
         else
         {
             savedata.l17.b4 = false;
         }
         if (savedata.l18.b1 && savedata.l18.b2 && savedata.l18.b3)
         {
             savedata.l18.b4 = true;
         }
         else
         {
             savedata.l18.b4 = false;
         }
         if (savedata.l19.b1 && savedata.l19.b2 && savedata.l19.b3)
         {
             savedata.l19.b4 = true;
         }
         else
         {
             savedata.l19.b4 = false;
         }
         if (savedata.l20.b1 && savedata.l20.b2 && savedata.l20.b3)
         {
             savedata.l20.b4 = true;
         }
         else
         {
             savedata.l20.b4 = false;
         }
     }
     [Serializable]
     public class savedata
     {
         public static class l1
         {
             public static bool completed, b1, b2, b3, b4;
         }
         public static class l2
         {
             public static bool completed, b1, b2, b3, b4;
         }
         public static class l3
         {
             public static bool completed, b1, b2, b3, b4;
         }
         public static class l4
         {
             public static bool completed, b1, b2, b3, b4;
         }
         public static class l5
         {
             public static bool completed, b1, b2, b3, b4;
         }
         public static class l6
         {
             public static bool completed, b1, b2, b3, b4;
         }
         public static class l7
         {
             public static bool completed, b1, b2, b3, b4;
         }
         public static class l8
         {
             public static bool completed, b1, b2, b3, b4;
         }
         public static class l9
         {
             public static bool completed, b1, b2, b3, b4;
         }
         public static class l10
         {
             public static bool completed, b1, b2, b3, b4;
         }
         public static class l11
         {
             public static bool completed, b1, b2, b3, b4;
         }
         public static class l12
         {
             public static bool completed, b1, b2, b3, b4;
         }
         public static class l13
         {
             public static bool completed, b1, b2, b3, b4;
         }
         public static class l14
         {
             public static bool completed, b1, b2, b3, b4;
         }
         public static class l15
         {
             public static bool completed, b1, b2, b3, b4;
         }
         public static class l16
         {
             public static bool completed, b1, b2, b3, b4;
         }
         public static class l17
         {
             public static bool completed, b1, b2, b3, b4;
         }
         public static class l18
         {
             public static bool completed, b1, b2, b3, b4;
         }
         public static class l19
         {
             public static bool completed, b1, b2, b3, b4;
         }
         public static class l20
         {
             public static bool completed, b1, b2, b3, b4;
         }
             public bool lvlsdone()
             {
                 if (l1.completed && l2.completed && l3.completed && l4.completed && l5.completed && l6.completed && l7.completed && l8.completed && l9.completed && l10.completed && l11.completed && l12.completed && l13.completed && l14.completed && l15.completed && l16.completed && l17.completed && l18.completed && l19.completed && l20.completed)
                 {
                     return true;
                 }
                 else
                 {
                     return false;
                 }
             }
             public bool allboxes()
             {
                 if (l1.b4 && l2.b4 && l3.b4 && l4.b4 && l5.b4 && l6.b4 && l7.b4 && l8.b4 && l9.b4 && l10.b4 && l11.b4 && l12.b4 && l13.b4 && l14.b4 && l15.b4 && l16.b4 && l17.b4 && l18.b4 && l19.b4 && l20.b4)
                 {
                     return true;
                 }
                 else
                 {
                     return false;
                 }
             }
             public bool alldone()
             {
                 if (allboxes() && lvlsdone())
                 {
                     return true;
                 }
                 else
                 {
                     return false;
                 }
             }
             public int farthestlvl()
             {
             if (!l1.completed)
             {
                 return 0;
             }
             else{
                 if (l2.completed)
                 {
                     if (l3.completed)
                     {
                         if (l4.completed)
                         {
                             if (l5.completed)
                             {
                                 if (l6.completed)
                                 {
                                     if (l7.completed)
                                     {
                                         if (l8.completed)
                                         {
                                             if (l9.completed)
                                             {
                                                 if (l10.completed)
                                                 {
                                                     if (l11.completed)
                                                     {
                                                         if (l12.completed)
                                                         {
                                                             if (l13.completed)
                                                             {
                                                                 if (l14.completed)
                                                                 {
                                                                     if (l15.completed)
                                                                     {
                                                                         if (l16.completed)
                                                                         {
                                                                             if (l17.completed)
                                                                             {
                                                                                 if (l18.completed)
                                                                                 {
                                                                                     if (l19.completed)
                                                                                     {
                                                                                         if (l20.completed)
                                                                                         {
                                                                                             return 20;
                                                                                         }
                                                                                         else
                                                                                         {
                                                                                             return 19;
                                                                                         }
                                                                                     }
                                                                                     else
                                                                                     {
                                                                                         return 18;
                                                                                     }
                                                                                 }
                                                                                 else
                                                                                 {
                                                                                     return 17;
                                                                                 }
                                                                             }
                                                                             else
                                                                             {
                                                                                 return 16;
                                                                             }
                                                                         }
                                                                         else
                                                                         {
                                                                             return 15;
                                                                         }
                                                                     }
                                                                     else
                                                                     {
                                                                         return 14;
                                                                     }
                                                                 }
                                                                 else
                                                                 {
                                                                     return 13;
                                                                 }
                                                             }
                                                             else
                                                             {
                                                                 return 12;
                                                             }
                                                         }
                                                         else
                                                         {
                                                             return 11;
                                                         }
                                                     }
                                                     else
                                                     {
                                                         return 10;
                                                     }
                                                 }
                                                 else
                                                 {
                                                     return 9;
                                                 }
                                             }
                                             else
                                             {
                                                 return 8;
                                             }
                                         }
                                         else
                                         {
                                             return 7;
                                         }
                                     }
                                     else
                                     {
                                         return 6;
                                     }
                                 }
                                 else
                                 {
                                     return 5;
                                 }
                             }
                             else
                             {
                                 return 4;
                             }
                         }
                         else
                         {
                             return 3;
                         }
                     }
                     else
                     {
                         return 2;
                     }
                 }
                 else
                 {
                     return 1;
                 }
             }
             }
       
     }
 }

i don't know what to do. please help!