i can assign all keys but the shift any ideas

so code works fully thats not problem no errors or anything but i cant assign a key to use shift all other keys work on keyboard and can be assigned

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.UI;
 
 public class keysetting : MonoBehaviour {
 
     private Dictionary<string, KeyCode> keys = new Dictionary<string, KeyCode>();
 
     public Text up, right, left, down, run, jump, interact, hideui;
 
     public GameObject menu;
     private bool disablemenu;
 
     private GameObject currentKey;
 
     private Color32 normal = new Color32(125, 3, 3, 255);
     private Color32 slected = new Color32(239, 116, 36, 255);
 
     public float speed = 5f;
     public GameObject character;
 
     //public CharacterController movementCode;
 
 
     // Use this for initialization
     void Start () {
         
         //not saving
         
 
         //working
         keys.Add("Up", (KeyCode)System.Enum.Parse(typeof(KeyCode), PlayerPrefs.GetString("Up", "W")));
         keys.Add("Right", (KeyCode)System.Enum.Parse(typeof(KeyCode), PlayerPrefs.GetString("Right", "D")));
         keys.Add("Left", (KeyCode)System.Enum.Parse(typeof(KeyCode), PlayerPrefs.GetString("Left", "A")));
         keys.Add("Down", (KeyCode)System.Enum.Parse(typeof(KeyCode), PlayerPrefs.GetString("Down", "S")));
         keys.Add("Run", (KeyCode)System.Enum.Parse(typeof(KeyCode), PlayerPrefs.GetString("Run", "Q")));
         keys.Add("Jump", (KeyCode)System.Enum.Parse(typeof(KeyCode), PlayerPrefs.GetString("Jump", "Space")));
         keys.Add("Interact", (KeyCode)System.Enum.Parse(typeof(KeyCode), PlayerPrefs.GetString("Interact", "E")));
         keys.Add("HideUI", (KeyCode)System.Enum.Parse(typeof(KeyCode), PlayerPrefs.GetString("HideUI", "Escape")));
 
         up.text = keys["Up"].ToString(); 
         right.text = keys["Right"].ToString();
         left.text = keys["Left"].ToString();
         down.text = keys["Down"].ToString();
         run.text = keys["Run"].ToString();
         jump.text = keys["Jump"].ToString();
         interact.text = keys["Interact"].ToString();
         hideui.text = keys["HideUI"].ToString();
 
         //movementCode = character.GetComponent <CharacterController> ();
     }
     
     // Update is called once per frame
     void Update () {
 
         //Movement Keys
         if (Input.GetKey(keys["Up"]))
         {
             //move action
             character.transform.localPosition += character.transform.forward * speed * Time.deltaTime;
             Debug.Log("Forword is pressed");
         }
         if (Input.GetKey(keys["Right"]))
         {
             character.transform.localPosition += character.transform.right * speed * Time.deltaTime;
             //move action
             Debug.Log("Right is pressed");
         }
         if (Input.GetKey(keys["Left"]))
         {
             character.transform.localPosition -= character.transform.right * speed * Time.deltaTime;
             //move action
             Debug.Log("Left is pressed");
         }
         if (Input.GetKey(keys["Down"]))
         {
             character.transform.localPosition -= character.transform.forward * speed * Time.deltaTime;
             //move action
             Debug.Log("Down is pressed");
         }
         if (Input.GetKey(keys["Run"]))
         {
             speed = 10f;
         }
         else
         {
             speed = 5f;
         }
 
             //MenuKeys
         if (Input.GetKeyDown(keys["HideUI"]))
         {
             //menu action
             disablemenu = !disablemenu;
             menu.SetActive(disablemenu);
             Debug.Log("HideUI is working");
         }
     }
 
     private void moveForward(float speed)
     {
         transform.localPosition += transform.forward * speed * Time.deltaTime;
     }
     private void moveBack(float speed)
     {
         transform.localPosition -= transform.forward * speed * Time.deltaTime;
     }
 
     private void moveRight(float speed)
     {
         transform.localPosition += transform.right * speed * Time.deltaTime;
     }
 
     private void moveLeft(float speed)
     {
         transform.localPosition -= transform.right * speed * Time.deltaTime;
     }
 
     void OnGUI()
     {
         if(currentKey != null)
         {
             Event e = Event.current;
             if(e.isKey)
             {
                 keys[currentKey.name] = e.keyCode;
                 currentKey.transform.GetChild(0).GetComponent<Text>().text = e.keyCode.ToString();
                 currentKey.GetComponent<Image>().color = normal;
                 currentKey = null;
             }
         }
     }
 
     public void ChangeKey( GameObject clicked)
     {
         if(currentKey != null)
         {
             currentKey.GetComponent<Image>().color = normal;
         }
         currentKey = clicked;
         currentKey.GetComponent<Image>().color = slected;
     }
 
     public void SaveKeys()
     {
         foreach (var key in keys)
         {
             PlayerPrefs.SetString(key.Key, key.Value.ToString());
             //saves each key
         }
 
         PlayerPrefs.Save();
     }
 }