Got an Unassigned error while trying to play my game.

Hi, I got this error while I was trying to play my game.

UnassignedReferenceException: The variable rightEdge of Enemy has not been assigned. You probably need to assign the rightEdge variable of the Enemy script in the inspector. UnityEngine.Transform.get_position () Enemy.Move () (at Assets/Scripts/Enemy.cs:184) PatrolState.Execute () (at Assets/Scripts/EnemyStates/PatrolState.cs:21) Enemy.Update () (at Assets/Scripts/Enemy.cs:115)

I can't figure out what happened.

Here's my Enemy.cs script:

using UnityEngine; using System.Collections; using System;

/// /// The enemy's class /// public class Enemy : Character {

 /// <summary>
 /// The enemy's current state
 /// changing this will change the enemys behaviour
 /// </summary>
 private IEnemyState currentState;

 /// <summary>
 /// The enemy's target
 /// </summary>
 public GameObject Target { get; set; }

 /// <summary>
 /// The enemy's melee range, at what range does the enemy need to use the sword
 /// </summary>
 [SerializeField]
 private float meleeRange;

 /// <summary>
 /// The enemy's throw range, how far can it start throwing knifes
 /// </summary>
 [SerializeField]
 private float throwRange;

 private Vector3 startPos;

 [SerializeField]
 private Transform leftEdge;

 [SerializeField]
 private Transform rightEdge;

 private Canvas healthCavas;

 /// <summary>
 /// Indicates if the enemy is in melee range
 /// </summary>
 public bool InMeleeRange
 {
     get
     {
         if (Target != null)
         {
             return Vector2.Distance(transform.position, Target.transform.position) <= meleeRange;

         }

         return false;
     }
 }

 /// <summary>
 /// Indicates if the enemy is in throw range
 /// </summary>
 public bool InThrowRange
 {
     get
     {
         if (Target != null)
         {
             return Vector2.Distance(transform.position, Target.transform.position) <= throwRange;

         }

         return false;
     }
 }

 /// <summary>
 /// Indicates if the enemy is dead
 /// </summary>
 public override bool IsDead
 {
     get
     {
         return healthStat.CurrentValue <= 0;
     }
 }

 // Use this for initialization
 public override void Start()
 {   //Calls the base start
     base.Start();

     this.startPos = transform.position;

     //Makes the RemoveTarget function listen to the player's Dead event
     Player.Instance.Dead += new DeadEventHandler(RemoveTarget);

     //Sets the enemy in idle state
     ChangeState(new IdleState());

     healthCavas = transform.GetComponentInChildren<Canvas>();
 }



 // Update is called once per frame
 void Update()
 {
     if (!IsDead) //If the enemy i alive
     {
         if (!TakingDamage) //if we aren't taking damage
         {
             //Execute the current state, this can make the enemy move or attack etc.
             currentState.Execute();
         }

         //Makes the enemy look at his target
         LookAtTarget();
     }

 }

 /// <summary>
 /// Removes the enemy's target
 /// </summary>
 public void RemoveTarget()
 {
     //Removes the target
     Target = null;

     //Changes the state to a patrol state
     ChangeState(new PatrolState());
 }

 /// <summary>
 /// Makes the enemy look at the target
 /// </summary>
 private void LookAtTarget()
 {
     //If we have a target
     if (Target != null)
     {
         //Calculate the direction
         float xDir = Target.transform.position.x - transform.position.x;

         //If we are turning the wrong way
         if (xDir < 0 && facingRight || xDir > 0 && !facingRight)
         {
             //Look in the right direction
             ChangeDirection();
         }
     }
 }

 /// <summary>
 /// Changes the enemy's state
 /// </summary>
 /// <param name="newState">The new state</param>
 public void ChangeState(IEnemyState newState)
 {
     //If we have a current state
     if (currentState != null)
     {
         //Call the exit function on the state
         currentState.Exit();
     }

     //Sets the current state as the new state
     currentState = newState;

     //Calls the enter function on the current state
     currentState.Enter(this);
 }

 /// <summary>
 /// Moves the enemy
 /// </summary>
 public void Move()
 {
     //If the enemy isn't attacking
     if (!Attack)
     {
         if ((GetDirection().x > 0 && transform.position.x < rightEdge.position.x) || (GetDirection().x < 0 && transform.position.x > leftEdge.position.x))
         {
             //Sets the speed to 1 to player the move animation
             MyAnimator.SetFloat("speed", 1);

             //Moves the enemy in the correct direction
             transform.Translate(GetDirection() * (movementSpeed * Time.deltaTime));
         }
         else if (currentState is PatrolState)
         {
             ChangeDirection();
         }

     }

 }

 /// <summary>
 /// Gets the current direction
 /// </summary>
 /// <returns>The direction</returns>
 public Vector2 GetDirection()
 {
     return facingRight ? Vector2.right : Vector2.left;
 }

 /// <summary>
 /// If the enemy collides with an object
 /// </summary>
 /// <param name="other">The colliding object</param>
 public override void OnTriggerEnter2D(Collider2D other)
 {
     //calls the base on trigger enter
     base.OnTriggerEnter2D(other);

     //Calls OnTriggerEnter on the current state
     currentState.OnTriggerEnter(other);
 }

 /// <summary>
 /// Makes the enemy take damage
 /// </summary>
 /// <returns></returns>
 public override IEnumerator TakeDamage()
 {
     if (!healthCavas.isActiveAndEnabled)
     {
         healthCavas.enabled = true;
     }

     //Reduces the health
     healthStat.CurrentValue -= 10;

     if (!IsDead) //If the enemy isn't dead then play the damage animation
     {
         MyAnimator.SetTrigger("damage");
     }
     else //If the enemy is dead then make sure that we play the dead animation
     {
         GameObject coin = (GameObject)Instantiate(GameManager.Instance.CoinPrefab, new Vector3(transform.position.x, transform.position.y + 5), Quaternion.identity);
         Physics2D.IgnoreCollision(GetComponent<Collider2D>(), coin.GetComponent<Collider2D>());
         MyAnimator.SetTrigger("die");
         yield return null;
     }
 }

 /// <summary>
 /// Removes the enemy from the game
 /// </summary>
 public override void Death()
 {
     MyAnimator.ResetTrigger("die");
     MyAnimator.SetTrigger("idle");
     healthStat.CurrentValue = healthStat.MaxVal;
     transform.position = startPos;
     healthCavas.enabled = false;
 }

 public override void ChangeDirection()
 {
     Transform tmp = transform.FindChild("EnemyHealthBarCanvas").transform;
     Vector3 pos = tmp.position;
     tmp.SetParent(null);

     base.ChangeDirection();

     tmp.SetParent(transform);
     tmp.position = pos;
 }

}

Patrol state script:

using UnityEngine; using System.Collections;

public class PatrolState : IEnemyState { private Enemy enemy; private float patrolTimer; private float patrolDuration;

 public void Enter(Enemy enemy)
 {
     this.enemy = enemy;
     patrolDuration = Random.Range(1, 10);
 }

 public void Execute()
 {
     Patrol();

     enemy.Move();

     if (enemy.Target != null && enemy.InThrowRange)
     {
         enemy.ChangeState(new RangedState());
     }
 }

 public void Exit()
 {
    
 }

 public void OnTriggerEnter(Collider2D other)
 {
     if (other.tag == "Edge")
     {
         enemy.ChangeDirection();
     }
     if (other.tag == "Knife")
     {
         enemy.Target = Player.Instance.gameObject;
     }
 }

 private void Patrol()
 {
     patrolTimer += Time.deltaTime;

     if (patrolTimer >= patrolDuration)
     {
         enemy.ChangeState(new IdleState());
     }
 }

}