Error C # script FloatingText in Unity.

Salve a tutti!

Sto lavorando ad un progetto 2d platform. Ho due script in C# col nome FloatingText e PointStar. Sulla console mi da 2 errori.

1° errore al numero 12, sullo script FloatingText con scritto questo:

NullReferenceException: Object reference not set to an instance of an object FloatingText.Show (System.String text, System.String style, IFloatingTextPositioner positioner) (at Assets/x ninja/CSharp Script/FloatingText.cs:12) PointStar.OnTriggerEnter2D (UnityEngine.Collider2D other) (at Assets/x ninja/CSharp Script/PointStar.cs:29)

 using UnityEngine;
 using System.Collections;
 
 public class FloatingText : MonoBehaviour 
 {
     private static readonly GUISkin Skin = Resources.Load<GUISkin>("GameSkin");
 
     public static FloatingText Show(string text, string style, IFloatingTextPositioner positioner)
     {
         var go = new GameObject("Floating Text");
         var floatingText = go.AddComponent<FloatingText>();
         floatingText.Style = Skin.GetStyle(style);
         floatingText._positioner = positioner;
         floatingText._content = new GUIContent(text);
         return floatingText;
     }
 
     private GUIContent _content;
     private IFloatingTextPositioner _positioner;
 
     public string Text { get { return _content.text; } set { _content.text = value; }}
     public GUIStyle Style { get; set; }
 
     public void OnGUI ()
     {
         var position = new Vector2();
         var contentSize = Style.CalcSize(_content);
         if (!_positioner.GetPosition(ref position, _content, contentSize))
         {
             Destroy(gameObject);
             return;
         }
 
         GUI.Label(new Rect(position.x, position.y, contentSize.x, contentSize.y), _content, Style);
     
     }
 }
 

I put the script where IFloatingTextPositioner assigns an error.

 using UnityEngine;
 using System.Collections;
 
 public interface IFloatingTextPositioner 
 {
 
     bool GetPosition(ref Vector2 position, GUIContent content, Vector2 size);
 }
 

I post also the script PointStar at number 29 gives an error.

 using UnityEngine;
 using System.Collections;
 
 public class PointStar : MonoBehaviour,  IPlayerRespawnListener
 {
 
     public GameObject Effect;
     public int PointsToAdd = 10;
     public AudioClip HitStarSound;
     public Animator Animator;
     public SpriteRenderer Renderer;
 
     private bool _isCollected;
 
     public void OnTriggerEnter2D(Collider2D other)
     {
 
         if (_isCollected)
             return;
 
         if (other.GetComponent<Player>() == null)
             return;
 
         if (HitStarSound != null)
             AudioSource.PlayClipAtPoint(HitStarSound, transform.position);
 
         GameManager.Instance.AddPoints(PointsToAdd);
         Instantiate(Effect, transform.position, transform.rotation);
         FloatingText.Show(string.Format("+{0}!", PointsToAdd), "PointStarText", new FromWorldPointTextPositioner(Camera.main, transform.position, 1.5f, 50));
     
         _isCollected = true;
         Animator.SetTrigger("Collect");
     }
 
     public void FinishAnimationEvent()
     {
         Renderer.enabled = false;
         Animator.SetTrigger("Reset");
     }
 
     public void OnPlayerRespawnInThisCheckpoint(Checkpoint checkpoint, Player player)
     {
         _isCollected = false;
         Renderer.enabled = true;
     }
     }
 

2nd error at number 27, again on the script FloatingText, saying this:

NullReferenceException: Object reference not set to an instance of an object FloatingText.OnGUI () (at Assets / x ninja / CSharp Script / FloatingText.cs: 27)

Thank You.