"NullReferenceException" while trying to draw a texture (C#)

Oh yeah, that's right, there's an "OnGUI" function.

It's not any errors anymore but nothing's showing up now, what could cause that?

Reading you question, I didn't find something that could cause this. Can you test this code below?

    public enum BarType
    {
        Health = 0,
        Armour = 1,
        Power = 2
     }
     public BarType barType;
     public Texture texture;
     public GameManager masterScript;
     private float health;
  
    void Awake ()
    {
         texture =  Resources.Load("yourtexturename") as Texture;
    }
 
     void Update () 
     {
        if (barType == BarType.Health)
        {
          health = (masterScript.health / masterScript.maxHealth);
        }
        else
        {
        }
     }
 
 void OnGUI ()
 {
    if (texture)
         GUI.DrawTextureWithTexCoords(new Rect(0, 0, 1, 1)
          , texture, new Rect(0,0, 1, health), false);
 
    else
      Debug.Log("texture not found");
 }

You just have to create a Resources folder and put your texture there. Another thing, if this condition

  if (barType == BarType.Health)
  {
       health = (masterScript.health / masterScript.maxHealth);
  }

didn't apply, what is the health value?

I'm not too into the idea of using "Resources.Load", because that would mean the script would be exclusive to that texture, and I don't want that, I have other bars in the game, and using the same script for all of them would really save me trouble.

I see, I'm just trying to figure out if Unity is finding your texture. Have you put some Debug.Log s to see if the texture was found?

Alright, I've tried the code anyway, and I'm afraid it didn't make a difference.

After taking the "Resources.Load" line out, I decided to test it again, I would expect it to log that the texture is missing, and that's what it did, so it's definetly accessing the function, it's not drawing anything when there IS a texture.