что не так с моим скриптом? Unity выдает ошибку Object reference not set to an instance of an object

private void Awake()
{
    rb = GetComponent<Rigidbody>();

    trailRL = trailRendererRL.GetComponent<Trail>();
    trailRR = trailRendererRR.GetComponent<Trail>();

    wheelFL.transform.localEulerAngles = Vector3.zero;
    wheelFR.transform.localEulerAngles = Vector3.zero;

    score.text = ((int)currentScore).ToString();
}