How to restart scene properly

It's not working on my computer. Is there something wrong with this code? By the way, Hurts is a function that is called when the enemy sends a message to the player (I'm pretty sure that the problem isn't in there, because I already used a Send$$anonymous$$essage for something else in the game and it works fine)

  using UnityEngine;
 using System.Collections;
 using UnityEngine.Scene$$anonymous$$anagement;
 //code and stuff
 void Hurts (int amount) {
         health -= amount;
         if (health <= 0) {
             Scene$$anonymous$$anager.LoadScene("dungeon 1");
         }
     }

It says "The type or namespace name 'Scene$$anonymous$$anagement' does not exist in the namespace 'UnityEngine'. Are you missing an assembly reference?"

Actually, to restart the CURRENT scene, you would do:

 Scene$$anonymous$$anager.LoadScene(GetActiveScene().name);