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I'm making a save system for my game, and have run into a NullReferenceException while loading the keybindings for one of the player objects (player 2). Since I used identical code to load the keybinds for player 1, and that one works fine, I believe that the problem comes from player 2 being inactive when the load script is run.

Here's most of the relevant code, based on Brackey's Save/Load tutorial:

    public string[] player1;
    public string[] player2;

    public GameData(AchievementsManager am, GameObject play2)
    {
        var p1 = play1.GetComponent<playerMovement>();
        var p2 = play2.GetComponent<playerMovement>(); 
        player1 = new string[4] { p1.up, p1.down, p1.left, p1.right};
        player2 = new string[4] { p2.up, p2.down, p2.left, p2.right};
    }

public class SaveManager : MonoBehaviour
{
    public GameObject play2;

    void Start()
    {
        GameData data = SaveSystem.loadGame();

        if (data != null)
        {
            var p1 = play1.GetComponent<playerMovement>();
            var p2 = play2.GetComponent<playerMovement>();
            string[] p1_controls = data.player1;
            string[] p2_controls = data.player2;
            p1.up = p1_controls[0]; p2.up = p2_controls[0];
            p1.down = p1_controls[1]; p2.down = p2_controls[1];
            p1.left = p1_controls[2]; p2.left = p2_controls[2];
            p1.right = p1_controls[3]; p2.right = p2_controls[3];
        }
    }
}

The error is on the line p2.up = p2_controls[0];, but I think that it's because there's a problem with play2.GetComponent<playerMovement>(); related to player 2 being inactive at startup. Is there a good way to fix this without making player 2 active at startup, or at least a way to better understand what exactly is causing the problem?

play2 is a GameObject referenced in the class header of SaveManager. play2 does have a playerMovement component that runs properly. I think that the NullReferenceException comes from the SaveManager not properly loading the information that it contains.

GameMakerJoe
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    Hi and welcome to stack overflow. It seems like `play2` does not have a `playerMovement` component attached to it and so `GetComponent` is returning `null`. There is not enough information in the question to understand why that might be. Can't help any more than that without more information in the question. – Ruzihm Nov 30 '20 at 22:39
  • Does this answer your question? [What is a NullReferenceException, and how do I fix it?](https://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-and-how-do-i-fix-it) – Ruzihm Nov 30 '20 at 22:39
  • Honestly, I don't have much more information than what I've provided. What I understand is that _GameData_ cannot access the _playerMovement_ on _play2_ for whatever reason. – GameMakerJoe Nov 30 '20 at 22:47
  • I assume `loadGame` calls `GameData(AchievementsManager am, GameObject play2)` somewhere. An explanation of where `play2` comes from would be a good start :p – Ruzihm Nov 30 '20 at 22:49

1 Answers1

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You should use in the GameData() an If(play2 != null) before trying to access to the P2 variable and assign it. And you can do the same thing in the Start () when you assign the P2 variables

Leoverload
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    This isn't the ideal solution, since play2 is never supposed to be null. That would mean no controls are linked to the player object and the game's multiplayer would be broken. I'm looking for a way to find the information that I'm looking for, not a way to ignore the fact that I found nothing. – GameMakerJoe Nov 30 '20 at 22:07