ArgumentOutOfRangeException:

[HedgeFlounder]

I’m not sure what’s wrong but I keep getting the following error:

ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index
System.ThrowHelper.ThrowArgumentOutOfRangeException (System.ExceptionArgument argument, System.ExceptionResource resource) (at :0)
System.ThrowHelper.ThrowArgumentOutOfRangeException () (at :0)
System.Collections.Generic.List`1[T].get_Item (System.Int32 index) (at :0)
EnemyPathing.Start () (at Assets/Scripts/EnemyPathing.cs:17)

This is my code

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class EnemyPathing : MonoBehaviour
{

[SerializeField] WaveConfig waveConfig;
List<Transform> waypoints;
[SerializeField] float moveSpeed = 2f;
int waypointIndex = 0;

// Start is called before the first frame update
void Start()
{
    waypoints = waveConfig.GetWaypoints();
    transform.position = waypoints[waypointIndex].transform.position;
}

// Update is called once per frame
void Update()
{
    Move();
}


    
private void Move()
{
    {
        if (waypointIndex <= waypoints.Count - 1)
        {
            var targetPosition = waypoints[waypointIndex].transform.position;
            var movementThisFrame = moveSpeed * Time.deltaTime;
            transform.position = Vector2.MoveTowards
                (new Vector2(transform.position.x, transform.position.y), new Vector2(targetPosition.x, targetPosition.y), movementThisFrame);

            if (transform.position == targetPosition)
            {
                waypointIndex++;
            }
        }
        else
        {
            Destroy(gameObject);
        }
    }
}

}

I’m not sure what the problem is. Here’s the code for my WaveConfig script too if it will help

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

[CreateAssetMenu(menuName = “Enemy Wave Config”)]
public class WaveConfig : ScriptableObject
{
[SerializeField] GameObject enemyPrefab;
[SerializeField] GameObject pathPrefab;
[SerializeField] float timeBetweenSpawns = 0.5f;
[SerializeField] float spawnRandomFactor = 0.3f;
[SerializeField] int numberOfEnemies = 5;
[SerializeField] float moveSpeed = 2f;

public GameObject GetEnemyPrefab() {return enemyPrefab;}
public List<Transform> GetWaypoints() 
    {
        var waveWaypoints = new List<Transform>();   
        
        foreach (Transform child in pathPrefab.transform)
            {
                waveWaypoints.Add(child);
            }
        
        return waveWaypoints;
    }
public float GetTimeBetweenSpawns() {return timeBetweenSpawns;}
public float GetSpawnRandomFactor() {return spawnRandomFactor;}
public int GetNumberOfEnemies() {return numberOfEnemies;}
public float GetMoveSpeed() {return moveSpeed;}

}

My game will run but it instantly destroys the enemy gameObject instead of having it follow the waypoints

[Nina]

Hi,

ArgumentOutOfRange / IndexOutOfRange exception means that the code tried to access a non-existent index in an array, List or another collection. The first index in an array and List is 0, hence the last index is the length minus 1. For example, if the array has got a length of 2, and the code tries to access index 2, you will get this error message because there are only two “slots” in the array: at index 0 and at index 1.

Have you already compared your code to the Lecture Project Changes which can be found in the Resources of this lecture?

Make sure there is a path, and the enemy must not get instantiated inside the shredder collider. Add Debug.Logs to your code to see what is going on during runtime.

[HedgeFlounder]

Thanks for the advice but it turns out that the problem was a lot simpler than any of that. I legitimately spent hours yesterday and about thirty minutes today looking over the script and only just now realized that there was nothing wrong with my script or my setup. I just forgot to save my WaveConfig script before running the game

[Nina]

@HedgeFlounder

I just forgot to save my WaveConfig script before running the game

Oops. Sometimes, the problem is so simple that we don’t even think about it.