MissingComponentException: There is no 'SpriteRenderer' attached to the "Balletjes(Clone)" game object, but a script is trying to access it - unity3d

Question

I get this error:
"MissingComponentException: There is no 'SpriteRenderer' attached to the "Balletjes(Clone)" game object, but a script is trying to access it."
I would like to assign the name of a sprite to the variable goldCoinPopUp. I searched a lot but nothing worked. Can anyone help me please?
ItemDragHandler
public class ItemDragHandler : MonoBehaviour, IDragHandler, IEndDragHandler
{
public GameObject prefab;
Vector2 original;
public void OnDrag(PointerEventData eventData)
{
Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
Debug.DrawRay(ray.origin, ray.direction * 100);
transform.position = Input.mousePosition;
}
public void OnEndDrag(PointerEventData eventData)
{
Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
RaycastHit hit;
if (Physics.Raycast(ray.origin, ray.direction, out hit, 100))
{
if (hit.collider.gameObject.name == "Terrain")
{
transform.gameObject.SetActive(false);
GameObject obj = Instantiate(prefab,hit.point, Quaternion.EulerAngles(0f, 3f, 0f)); // 3d object
obj.AddComponent<GenerateResources>(); // link to GenerateResources script
Vector3 img = new Vector3(0, 8.66f, 0);
obj.transform.position += img;
}
else
{
transform.localPosition = original;
}
}
else
{
transform.localPosition = original;
}
}
void Start ()
{
original = transform.localPosition;
}
}
GenerateResources
public class GenerateRessources : MonoBehaviour
{
private int ressourcesInBuilding;
public int valueWhenCollect = 10;
private float timerExtraRessource;
public float generateRate = 4;
public SpriteRenderer goldCoinPopUp;
private GameObject currentGameObject;
private GameObject Inventory;
void Start ()
{
goldCoinPopUp = GetComponent<SpriteRenderer>();
goldCoinPopUp.enabled = false;
currentGameObject = gameObject.GetComponent<GameObject>();
Inventory = GameObject.Find("Inventory");
}
void Update ()
{
AddResource();
getResources();
}
private void AddResource()
{
timerExtraRessource += Time.deltaTime;
if (timerExtraRessource >= generateRate)
{
ressourcesInBuilding++;
timerExtraRessource = 0;
if (ressourcesInBuilding >= valueWhenCollect)
{
goldCoinPopUp.enabled = true;
}
}
}
private void getResources()
{
if (Input.touchCount > 0)
{
Touch touch = Input.touches[0];
if (touch.phase == TouchPhase.Began)
{
RaycastHit hit;
Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
if (Physics.Raycast(ray, out hit, 100f))
{
if (hit.transform.gameObject != null)
{
}
}
}
}
if (Input.GetMouseButtonDown(0))
{
RaycastHit hit;
Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
if (Physics.Raycast(ray, out hit, 100f))
{
if (hit.transform.gameObject != currentGameObject)
{
if (goldCoinPopUp.enabled == true)
{
goldCoinPopUp.enabled = false;
Inventory.GetComponent<GameController>().Gold += ressourcesInBuilding;
ressourcesInBuilding = 0;
}
}
}
}
}
}

Answer 1

Your code depends on SpriteRenderer being present, while your prefab does not have one. You can work around this problem by adding the following attribute before your class definiton
[RequireComponent(typeof(SpriteRenderer))]
public class GenerateRessources : MonoBehaviour
However the automatically added SpriteRenderer will have no sprite attached, hence a better solution would be to make sure your prefab does indeed have a reasonable sprite attached