When I Enter the script and hit Create it gives me an error

When I insert this script:

         PlayerPrefs.SetInt(((VitalName)cnt).ToString() +" - Base Value" ,pcClass.GetVital(cnt).BaseValue);

I have asked many people and it only occurs on Windows 7 64-bits

The error I get When I press Create Button is:

NullReferenceException: Object reference not set to an instance of an object GameSettings.SaveCharacterData () (at Assets/Standard Assets/C# scripts/Character statistics/GameSettings.cs:32) CharacterGenerator.DisplayCreateButton () (at Assets/Standard Assets/C# scripts/Character statistics/CharacterGenerator.cs:148) CharacterGenerator.OnGUI () (at Assets/Standard Assets/C# scripts/Character statistics/CharacterGenerator.cs:56)

I think it has something to do with the vital script it is:

 public class Vital : ModifiedStat {
         private int _curValue;
         
         public Vital(){
             _curValue = 0;
             ExpToLevel = 40;
             LevelModifier = 1.1f;
         }
             public int CurValue{
             get{
                 if(_curValue > AddjustedBaseValue)
                     _curValue = AddjustedBaseValue;
                 
                 return _curValue;
             }
             set{_curValue = value;}
         }
     }
     public enum VitalName {
         Energy,
         Mana,
         Health
     }

Both the scripts are in C# Can someone help me? please