The type or namescape name 'ModifyingAttribute' could not be found.

Hey guys, I've gotten this error (error CS0246) and I'm a little confused because I don't see anything wrong with the code? I've had someone else proof check it to make sure it is actually okay, but he can't see an error either. Are be both just being stupid?

The error is on this code:

 private void SetupVitalModifiers() {
         //health
         ModifyingAttribute healthModifier = new ModifyingAttribute();
         healthModifier.attribute = GetPrimaryAttribute((int)AttributeName.Constitution);
         healthModifier.ratio = .5f;
         
         GetVital((int)VitalName.Health).AddModifier(healthModifier);
         //energy
         ModifyingAttribute energyModifier = new ModifyingAttribute();
         energyModifier.attribute = GetPrimaryAttribute((int)AttributeName.Constitution);
         energyModifier.ratio = .5f;
         
         GetVital((int)VitalName.Energy).AddModifier(energyModifier);
         //mana
         ModifyingAttribute manaModifier = new ModifyingAttribute();
         manaModifier.attribute = GetPrimaryAttribute((int)AttributeName.Willpower);
         manaModifier.ratio = .5f;
         
         GetVital((int)VitalName.Mana).AddModifier(manaModifier);
     }

Here's the full code:

 using UnityEngine;
 using System.Collections;
 using System;                                // Added to access the enum class
 
 public class BaseCharacter : MonoBehaviour {
     private string _name;
     private int _level;
     private uint _freeExp;
     
     private Attribute[] _primaryAttribute;
     private Vital[] _vital;
     private Skill[] _skill;
     
     public void Awake() {
         _name = string.Empty;
         _level = 0;
         _freeExp = 0;
         
         _primaryAttribute = new Attribute[Enum.GetValues(typeof(AttributeName)).Length];
         _vital = new Vital[Enum.GetValues(typeof(VitalName)).Length];
         _skill = new Skill[Enum.GetValues(typeof(VitalName)).Length];
     }
         
     // Use this for initialization
     void Start () {
     
     }
     
     // Update is called once per frame
     void Update () {
     
     }
     
     public string Name {
         get{ return _name; }
         set{ _name = value; }
     }
     
     public int Level {
         get{ return _level; }
         set{ _level = value; }
     }
     
     public uint FreeExp {
         get{ return _freeExp; }
         set{ _freeExp = value; }
     }
     
     public void AddExp(uint exp) {
         _freeExp += exp;
             
         CalculateLevel();
     }
     
     
     // Take average of all of the players skills and assign that as the player level
     public void CalculateLevel() {
     }
     
     private void SetupPrimaryAttributes() {
         for(int cnt = 0; cnt < _primaryAttribute.Length; cnt++) {
             _primaryAttribute[cnt] = new Attribute();
         }
     }
     
     private void SetupVitals() {
         for(int cnt = 0; cnt < _vital.Length; cnt++) {
             _vital[cnt] = new Vital();
         }
     }
     private void SetupSkills() {
         for(int cnt = 0; cnt < _skill.Length; cnt++) {
             _skill[cnt] = new Skill();
         }
     }
     
     public Attribute GetPrimaryAttribute(int index) {
         return _primaryAttribute[index];
     }
     
         public Vital GetVital(int index) {
         return _vital[index];
     }
     
         public Skill GetSkill(int index) {
         return _skill[index];
     }
     
     private void SetupVitalModifiers() {
         //health
         ModifyingAttribute healthModifier = new ModifyingAttribute();
         healthModifier.attribute = GetPrimaryAttribute((int)AttributeName.Constitution);
         healthModifier.ratio = .5f;
         
         GetVital((int)VitalName.Health).AddModifier(healthModifier);
         //energy
         ModifyingAttribute energyModifier = new ModifyingAttribute();
         energyModifier.attribute = GetPrimaryAttribute((int)AttributeName.Constitution);
         energyModifier.ratio = .5f;
         
         GetVital((int)VitalName.Energy).AddModifier(energyModifier);
         //mana
         ModifyingAttribute manaModifier = new ModifyingAttribute();
         manaModifier.attribute = GetPrimaryAttribute((int)AttributeName.Willpower);
         manaModifier.ratio = .5f;
         
         GetVital((int)VitalName.Mana).AddModifier(manaModifier);
     }
     private void SetupSkillModifiers() {
     }
 }

And here is the code to where BaseCharacter.cs is relating to:

 using System.Collections.Generic;
 
 public class ModifiedStat : BaseStat {
     private List<ModifyingAttribute> _mods;            //A list of Attributes that modify this stat
     private int _modValue;                            //The amount added to the baseValue from the modifiers
     
     public ModifiedStat() {
         _mods = new List<ModifyingAttribute>();
         _modValue = 0;
     }
     
     public void AddModifier( ModifyingAttribute mod) {
         _mods.Add (mod);
     }
     
     private void CalculateModValue() {
         _modValue = 0;
         
         if(_mods.Count > 0)
             foreach(ModifyingAttribute att in _mods)
                 _modValue += (int)(att.attribute.AdjustedBaseValue * att.ratio);
     }
     
     public new int AdjustedBaseValue{
                 get { return BaseValue + BuffValue + _modValue; }
     }
 
 public struct ModifyingAttribute {
     public Attribute attribute;
     public float ratio;
     }
 }

Thanks in advance!