Bool always returning true even if should return false.

As said above the containsallitems bool is returning false all the time, even if it should return true.

Code:

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 using System.Linq;
 
 public class PlayerInventory : MonoBehaviour {
     
     public int MaxInventory = 26;
     
     public List<Item> InventoryItems = new List<Item>();
     
     void OnGUI(){
         if (GUILayout.Button ("+5 Wood")) {
             AddItem(ItemConstructors.Wood());
             AddItem(ItemConstructors.Wood());    
             AddItem(ItemConstructors.Wood());    
             AddItem(ItemConstructors.Wood());    
             AddItem(ItemConstructors.Wood());
         }
         if (GUILayout.Button ("Craft Wall")) {
             Craft(CraftingRecipes.WoodenWall());
         }
         
     }
     
     
     public void AddItem(Item _item){
         if (InventoryItems.Count < MaxInventory) {
             InventoryItems.Add(_item);
             SaveItems();
         }
     }
     
     public void RemoveItem(Item _item){
         InventoryItems.Remove (_item);
     }
     
     public void UseItem(Item _item){
         if (_item.ItemType == "Food") {
             ConsumeItem(_item);
         }
         SaveItems();
     }
     
     public void ConsumeItem(Item _item){
         if (_item.ItemDur > 1) {
             _item.ItemDur--; 
         }
         else if(_item.ItemDur <= 1){
             RemoveItem(_item);
         }
     }
     
     public void SaveItems(){
         for (int i = 0; i<MaxInventory; i++) {
             PlayerPrefs.SetString("Itemn"+i,InventoryItems[i].ItemName); 
             PlayerPrefs.SetString("Itemt"+i,InventoryItems[i].ItemType);
             PlayerPrefs.SetInt("Itemv"+i,InventoryItems[i].ItemValue);
             PlayerPrefs.SetInt("Itemd"+i,InventoryItems[i].ItemDur);
         }
         LoadItems ();
     }
     public void LoadItems(){
         InventoryItems.Clear();
         for (int i = 0; i<MaxInventory; i++) {
             Item it = new Item();
             it.ItemName = PlayerPrefs.GetString("Itemn"+i);
             it.ItemType = PlayerPrefs.GetString("Itemt"+i);
             it.ItemValue = PlayerPrefs.GetInt("Itemv"+i);
             it.ItemDur = PlayerPrefs.GetInt("Itemd"+i);
             if(it.ItemName.Length <= 2 && it.ItemType.Length <= 2){
             }
             else{
                 InventoryItems.Add(it);
             }
         }
     }
     
     public void Craft(CraftingItem Recipe){
         bool canCraft = ContainsAllItems (InventoryItems,Recipe.InputItem);
         if(canCraft){
             if(InventoryItems.Count < MaxInventory){
                 List<Item> list = new List<Item>();
                 list = InventoryItems.Except(Recipe.InputItem).ToList();
                 InventoryItems = list;
                 AddItem(Recipe.OutputItem);
             }
             else{
                 Debug.Log("Not enough space!");
             }
         }
         else{
             Debug.Log("Invalid Items.");
         }
     }
 
     public static bool ContainsAllItems(List<Item> a, List<Item> b)
     {
         return !b.Except(a).Any();
     }
     
 }

CRAFTING ITEM

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 
 public class CraftingItem
 {
     public Item OutputItem = new Item();
     public List<Item> InputItem = new List<Item>();
 }

CRAFTING RECIPES

 using UnityEngine;
 using System.Collections;
 using System.Collections.Generic;
 
 public static class CraftingRecipes {
 
     public static CraftingItem WoodenWall(){
         CraftingItem ct = new CraftingItem ();
         ct.InputItem.Add (ItemConstructors.Wood());
         ct.InputItem.Add (ItemConstructors.Wood());
         ct.OutputItem = ItemConstructors.WoodenWall ();
         return ct;
     }
 
     public static CraftingItem StoneWall(){
         CraftingItem ct = new CraftingItem ();
         ct.InputItem.Add (ItemConstructors.Stone());
         ct.InputItem.Add (ItemConstructors.Stone());
         ct.OutputItem = ItemConstructors.StoneWall ();
         return ct;
     }
 
     public static CraftingItem FirePit(){
         CraftingItem ct = new CraftingItem ();
         ct.InputItem.Add (ItemConstructors.Wood());
         ct.InputItem.Add (ItemConstructors.Stone());
         ct.OutputItem = ItemConstructors.FirePit ();
         return ct;
     }
 
 }

ITEM

 using UnityEngine;
 using System.Collections;
 
 [System.Serializable]
 public class Item
 {
     public string ItemName = "";
     public string ItemType = "";
     public int ItemValue = 0;
     public int ItemDur = 0;
 }

ITEM CONSTRUCTORS

 using UnityEngine;
 using System.Collections;
 
 public static class ItemConstructors
 {
 
     /*
      * 
      * Crafting resources.
      *
      */
 
 
     public static Item Wood(){
         Item it = new Item ();
         it.ItemName = "Wood";
         it.ItemType = "Crafting";
         it.ItemDur = 1;
         it.ItemValue = 1;
         return it;
     }
 
     public static Item Stone(){
         Item it = new Item ();
         it.ItemName = "Stone";
         it.ItemType = "Crafting";
         it.ItemDur = 1;
         it.ItemValue = 1;
         return it;
     }
     
     /*
      * 
      *Buildables.
      * 
      */
 
     public static Item WoodenWall(){
         Item it = new Item ();
         it.ItemName = "Wooden Wall";
         it.ItemType = "Build";
         it.ItemDur = 100;
         it.ItemValue = 1;
         return it;
     }
 
     public static Item StoneWall(){
         Item it = new Item ();
         it.ItemName = "Stone Wall";
         it.ItemType = "Build";
         it.ItemDur = 250;
         it.ItemValue = 1;
         return it;
     }
 
     public static Item FirePit(){
         Item it = new Item ();
         it.ItemName = "Fire Pit";
         it.ItemType = "Build";
         it.ItemDur = 50;
         it.ItemValue = 1;
         return it;
     }
 
     /*
      * 
      * Food/Consumables.
      * 
      */
     public static Item Apple(){
         Item it = new Item ();
         it.ItemName = "Apple";
         it.ItemType = "Food";
         it.ItemDur = 1;
         it.ItemValue = 1;
         return it;
     }
 
     public static Item Bread(){
         Item it = new Item ();
         it.ItemName = "Bread";
         it.ItemType = "Food";
         it.ItemDur = 2;
         it.ItemValue = 1;
         return it;
     }
 }