Object reference not set to an instance of an object after build to android

Question

I have some error and I don't know why after adding some localization system to my game turn null reference at the gameplay

and this my GameManager script it, I think I have done with an object reference in unity editor but after build to android that the object become null reference

private void Start()
{
    LM = FindObjectOfType<LocalizationManager>();
    audioManager = FindObjectOfType<AudioManager>();
    questionManager = FindObjectOfType<_questionManager>();
    LevelSelect = FindObjectOfType<SelecLevel>();
    Select = FindObjectOfType<_CharacterSelect>();
    sliderChanges = FindObjectOfType<SliderChanges>();

    onlepel = LevelSelect.levelIndex + 1;
    IndexLevel = LevelSelect.levelIndex;
    getPlayerData();

    Timecount = GameObject.FindGameObjectWithTag("TimeCount");

    if (LM.Bahasa)
    {
        category = GameObject.Find("QuestionManagerIndonesia").GetComponent<_questionManager>().category;
    }
    else
    {
        category = GameObject.Find("QuestionManagerEnglish").GetComponent<_questionManager>().category;
    }
    moneyAmount = PlayerPrefs.GetFloat("MoneyAmount");


    if (unansweredQuestion == null || unansweredQuestion.Count == 0)
    {
        thisQuestions = category[IndexLevel].questions;
        unansweredQuestion = new List<Question>(thisQuestions);

        TrueAnswerText.text = "CORRECT";
        FalseAnswerText.text = "WRONG!";

        //unansweredQuestion = new List<Question>(questions);
    }
    if (TrueAnswerText != null)
        TrueAnswerText.text = "CORRECT";
    if (FalseAnswerText != null)
        FalseAnswerText.text = "WRONG!";

    TrueCount = 0;
    if (FactText != null)
        setCurrentQuestion();


}

well .. it happens either here `LevelSelect.levelIndex` or here `category[IndexLevel].questions` ... Where and how do you initialize the `category`? Or in `TrueAnswerText.text =` and `FalseAnswerText.text =` - the ones that happen before the `null` check ... — derHugo, Sep 23 '19 at 06:58
thanks, I found the problem, it's because I have an instance the object and became static so that's `category` can't load 2 references. `static _questionManager instance;` `if (instance != null) { Destroy(gameObject); } else instance = this; DontDestroyOnLoad(gameObject);` — , Sep 23 '19 at 07:07

score 1 · Answer 1 · answered Sep 23 '19 at 06:53

1

Put your start block into a try catch

EG.:

try
{
    // A class that has an int field called var
    Test asd = null;
    // whops null reference
    int var = asd.var;
}
catch (NullReferenceException ex)
{
     Console.WriteLine(ex.StackTrace);
}

StackTrace porperty should tell you at which line your nullreference happened.

To enable this feature in release mode check this: Display lines number in Stack Trace for .NET assembly in Release mode

answered Sep 23 '19 at 06:53

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thanks, I found the problem, it's because I have an instance the object and became static so that's `category` can't load 2 references. so I delete that and only put `DontDestroyOnload ` `static _questionManager instance;` `if (instance != null) { Destroy(gameObject); } else instance = this; DontDestroyOnLoad(gameObject);` – Sep 23 '19 at 07:10

Object reference not set to an instance of an object after build to android

1 Answers1