C# NullReferenceException Error

Unity Engine
1

So I am trying to create an audio options menu however it is coming up with the following error:

NullReferenceException: Object reference not set to an instance of an object
AudioOptions_Master.Start () (at Assets/Scripts/UI/Standard Menus/Options Menu/Sound/AudioOptions_Master.cs:26)

However, everything is assigned in the inspector.

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

public class AudioOptions_Master : MonoBehaviour
{
    public Button BTN_MuteMaster;
    public Button BTN_TestMaster;

    public Color Color_BTN_Sound;
    public Color Color_BTN_Muted;
    public Color Color_TXT_Sound;
    public Color Color_TXT_Muted;

    public float FLT_Master;
    public float FLT_MasterBackup;

    public Slider SLI_Master;

    public Text TXT_Master;
    public Text TXT_BTN_MuteMaster;

    public void Start ( )
    {
        BTN_MuteMaster.onClick.AddListener ( Mute_Master );
    }

    public void Mute_Master ( )
    {
        if ( FLT_Master == 0.0f )
        {
            // Restore Backup
            FLT_Master = FLT_MasterBackup;

            // Change Color
            BTN_MuteMaster.GetComponent<UnityEngine.UI.Image> ( ).color = Color_BTN_Sound;
        }

        else
        {
            // Set Backup
            FLT_MasterBackup = FLT_Master;

            // Mute Master Audio
            FLT_Master = 0.0f;

            // Change Color
            BTN_MuteMaster.GetComponent<UnityEngine.UI.Image> ( ).color = Color_BTN_Muted;
        }
    }
}
2

Surely, BTN_MuteMaster must be null…
Put a break point on line 26 and inspect.
Alternatively just put: Debug.Log("Is it null? " + (BTN_MuteMaster == null)); before it.

3

Ah found the problem. it was simply a case of having the script on the button as well as the audio handler object I made. Thanks for the help though :slight_smile: