NullReferenceException: Object reference not set to an instance of an Object

Unity Engine
1

Hi! I’m new here and also with Unity and programming in C#… So I have some trouble.

I want to take a font asset (TMP_FontAsset of TextMeshPro) from the inspector using my class Manager, and then change every text with the FontText script attached, so its font is the one I took from the inspector.

Here is what I use for this in Manager.cs:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.SceneManagement;
using TMPro;
using System;

public class Manager : MonoBehaviour {

    // ...

    public static Manager Instance { set; get; }

    [Header("Global Text")]
    public TMP_FontAsset GlobalFont;

    // ...

}

And this is the FontText script:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using TMPro;

public class FontText : MonoBehaviour {

    private TextMeshProUGUI m_TextMeshPro;
    private TMP_FontAsset m_Font = Manager.Instance.GlobalFont;

    void Start () {
        UpdateFontText();   
    }
 
    void UpdateFontText () {
       
        if (m_TextMeshPro == null && GetComponent<TextMeshProUGUI>() != null) {

            m_TextMeshPro = GetComponent<TextMeshProUGUI>();
  
            m_TextMeshPro.font = m_Font;

        }

    }
}

So the thing is that with this code it works, it changes the font, but it gives me a NullReferenceException: Object reference not set to an instance of an Object

I hope someone could help me, I have no idea why this happens… I need the code to be correct even if it apparently works. I tried to assign the font (m_Font = Manager.Instance.GlobalFont; ) in the Start() function or in the Update(), but then the font doesn’t change and the error is still there… Any ideas?

Thank you very much!

Edited:

Here are the lines of the error:

NullReferenceException: Object reference not set to an instance of an object
FontText…ctor () (at Assets/Scripts/FontText.cs:9)

2

Please paste the entire error message, including the lines that appear below that one when you select it. It includes vital information, especially the line number of the error.

3

at line 20 of FontText, put this:

Debug.Log(m_TextMeshPro);

if that comes up as Null… then there is your problem. the component does not exist.

Tip:
Always do null refernce checks before using variables, unless, you apply this:

[RequireComponent(ComponentNameHere)]

Even then, its not a bad idea. :wink:

4

Read line 17… there is a null check there.

5

It would be good to see what line the error is on and the entire error.

I’m wondering if Manager.Instance is null though.

6

Hi, thanks for the answers! I edited the post with the lines of this error.

7

Yeah, then I stand by what I said.

Manager.Instance is probably null.

Your Manager class needs

Instance = this; in the Awake method.

Then in FontText you should have

m_Font = Manager.Instance.GlobalFont;

In start if you really want to go that route, but honestly you could just assign the font straight from the manager class

m_TextMeshPro.font = Manager.Instance.GlobalFont;
1 Like
8

Oooh! Thank you Brathnann, thank you very much!
I was using too much lines for something that simple, I just took the last line you wrote and finally it works perfect, with no errors!

Love you! :_)