restart level when dead with delay

Hello guys, i'm struggling with something. after my player loses all his lives, i want him to restart the level with a delay i did add a yield but i keep getting an error i don't know what to do

this is the error

 Assets/Scripts/PlayerController.cs(56,14): error CS1624: The body of `PlayerController.SetCountText()' cannot be an iterator block because `void' is not an iterator interface type
 

and here is my script

 using UnityEngine;
 using System.Collections;
 
 public class PlayerController : MonoBehaviour
 {
 
     public float speed;
     public GUIText countText;
     public GUIText winText;
     public GUIText LiveText;
     public GUIText LoseText;
     public AudioClip LoseAudio;
     public AudioClip LiveSound;
     public AudioClip PickUpSound;
     public AudioClip WinAudio; 
     private int PickUpCount;
     public int LiveCount;
 
 
     void start ()
     {
         PickUpCount = 0;
         LiveCount = 3;
         SetCountText ();
         winText.text = "";
     }
 
     void FixedUpdate ()
     {
         float moveHorizontal = Input.GetAxis("Horizontal");
         float moveVertical = Input.GetAxis("Vertical");
         
         Vector3 movement = new Vector3(moveHorizontal, 0.0f, moveVertical);
         
         rigidbody.AddForce(movement * speed * Time.deltaTime);
     }
 
     void OnTriggerEnter(Collider other)
     {
         if(other.gameObject.tag == "PickUp")
         {
             AudioSource.PlayClipAtPoint(PickUpSound, new Vector3(5, 2, 2));
             other.gameObject.SetActive(false);
             PickUpCount = PickUpCount + 1;
             SetCountText ();
         }
         if(other.gameObject.tag == "Obstacle")
         {
             AudioSource.PlayClipAtPoint(LiveSound, new Vector3(5, 2, 2));
             other.gameObject.SetActive(false);
             LiveCount = LiveCount - 1;
             SetCountText ();
         }
     }
     
     void SetCountText()
     {
             countText.text = "Blocks: " + PickUpCount.ToString ();
             if (PickUpCount >= 16) {
                     AudioSource.PlayClipAtPoint (WinAudio, new Vector3 (5, 2, 2));
                     winText.text = ("WE MADE IT!");
             }    
             {
             LiveText.text = "Lives: " + LiveCount.ToString ();
             if (LiveCount == 0) {    
                     AudioSource.PlayClipAtPoint (LoseAudio, new Vector3 (5, 2, 2));
                     LoseText.text = ("TRY AGAIN BRO");
                     LiveCount = 0;
                     yield return new WaitForSeconds(5f);
                     Application.LoadLevel("level 2");
             }        
             }
     }    
 }
 
 

i'd love to get some help here