Need help fixing a null reference exception!

NullReferenceException: Object reference not set to an instance of an object
Player.Die () (at Assets/Scripts/Player/Player.cs:211)
Player.TakeDamage (Single value, DamageType damageType) (at Assets/Scripts/Player/Player.cs:244)
EnemyProjectile.OnTriggerEnter (UnityEngine.Collider collision) (at Assets/Scripts/Projectile/EnemyProjectile.cs:10)

This is the error I get when I play the game and die (I’m trying to make a death screen menu). I’m trying to reference the menu which is scripted on my PlayerUI script from my Player script, which holds the script for dying so I have this under my Player script:

#region Die
	public void Die () {
             PlayerUI.Death ();
        }
#endregion

#region Take Damge
	public void TakeDamage (float value, DamageType damageType) {
		if (Auras.AuraIsActive<RockArmorAura>()) {
			Aura rockArmor = Auras.GetAura<RockArmorAura>();
			rockArmor.RemoveStack(1, false);
		}
		else
			switch (damageType) {
				case DamageType.Air:
					Health -= value * Auras.AirTaken;
					break;
				case DamageType.Arcane:
					Health -= value * Auras.ArcaneTaken;
					break;
				case DamageType.Earth:
					Health -= value * Auras.EarthTaken;
					break;
				case DamageType.Fire:
					Health -= value * Auras.FireTaken;
					break;
				case DamageType.Water:
					Health -= value * Auras.WaterTaken;
					break;
			}
		
		if (Health <= 0) {
			Die ();
		}
	}
	#endregion

and then I have this under my PlayerUI script:

            public void Death () {
		      Time.timeScale = 0;
		      MouseLook.Enabled = false;
		      ViewMouseLook.Enabled = false;
		      NGUITools.SetActive (DeathScreen, true);
               }

I’ll answer my own question,

void Start(){ PlayerUI = this.GetComponent(); } //needed to add this so it could find the component and reference it otherwise i got null