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.

public static FloatingText_Show(string text, string style, IFloatingTextPositioner positioner)

replace this line first