2D Platformer - Problem with object that kills, then restarts after build

Questions & Answers
1

Hiya. I’m new to Unity and C# and have been following a youtuber’s tutorials on making a 2D endless runner game. In Unity, everything works perfectly, but when I build it. the ‘deathzone’ doesn’t work. I built it with developer version and this is what comes up:

UnityException: GameObject has undefined tag!

I don’t know how I’m meant to fix it. The code is below, or here: http://collabedit.com/42yp8

For the player controller:

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

public class Controls : MonoBehaviour {

    public float moveSpeed;
    private float moveSpeedStore;
    public float speedMultiplier;

    public float speedIncreaseMilestone;
    private float speedIncreaseMilestoneStore;

    private float speedMilestoneCount;
    private float speedMilestoneCountStore;

    public float jumpForce;

    public float jumpTime;
    private float jumpTimeCounter;

    private Rigidbody2D myRigidbody;

    public bool grounded;
    public LayerMask whatIsGround;

    private Collider2D myCollider;

    private Animator myAnimator;

    public GameManager theGameManager;

    // Use this for initialization
    void Start () {
        myRigidbody = GetComponent<Rigidbody2D>();

        myCollider = GetComponent<Collider2D>();

        myAnimator = GetComponent<Animator>();

        jumpTimeCounter = jumpTime;

        moveSpeedStore = moveSpeed;
        speedMilestoneCountStore = speedMilestoneCount;
        speedIncreaseMilestoneStore = speedIncreaseMilestone;
    }

    // Update is called once per frame
    void Update() {

        grounded = Physics2D.IsTouchingLayers(myCollider, whatIsGround);

        if(transform.position.x > speedMilestoneCount)
        {
            speedMilestoneCount += speedIncreaseMilestone;

            speedIncreaseMilestone = speedIncreaseMilestone * speedMultiplier;

            moveSpeed = moveSpeed * speedMultiplier;
        }

        myRigidbody.velocity = new Vector2(moveSpeed, myRigidbody.velocity.y);

        if (Input.GetKeyDown(KeyCode.W) || Input.GetKeyDown(KeyCode.Space) || Input.GetKeyDown(KeyCode.UpArrow) || Input.GetMouseButtonDown(0))
        {
            if (grounded)
            {
                myRigidbody.velocity = new Vector2(myRigidbody.velocity.x, jumpForce);
            }
        }

        if (Input.GetKey(KeyCode.Space) || Input.GetKey(KeyCode.W) || Input.GetKeyDown(KeyCode.UpArrow) || Input.GetMouseButton(0))
        {
            if(jumpTimeCounter > 0)
            {
                myRigidbody.velocity = new Vector2(myRigidbody.velocity.x, jumpForce);
                jumpTimeCounter -= Time.deltaTime;
            }
        }

        if (Input.GetKeyUp(KeyCode.Space) || Input.GetMouseButtonUp(0) || Input.GetKeyDown(KeyCode.UpArrow) || Input.GetKeyUp(KeyCode.W))
        {
            jumpTimeCounter = 0;
        }

        if(grounded)
        {
            jumpTimeCounter = jumpTime;
        }

        myAnimator.SetFloat("Speed", myRigidbody.velocity.x);
        myAnimator.SetBool("Grounded", grounded);
    }

    void OnCollisionEnter2D(Collision2D other)
    {
        if (other.gameObject.tag == "killbox")
        {
            theGameManager.RestartGame();
            moveSpeed = moveSpeedStore;
            speedMilestoneCount = speedMilestoneCountStore;
            speedIncreaseMilestone = speedIncreaseMilestoneStore;
        }
    }
}

Game Manager

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

public class GameManager : MonoBehaviour {

    public Transform platformGenerator;
    private Vector3 platformStartPoint;

    public Controls thePlayer;
    private Vector3 playerStartPoint;

    private PlatformKiller[] platformList;

    private ScoreManager theScoreManager;

    // Use this for initialization
    void Start ()
    {
        platformStartPoint = platformGenerator.position;
        playerStartPoint = thePlayer.transform.position;

        theScoreManager = FindObjectOfType<ScoreManager>();
    }
    
    // Update is called once per frame
    void Update ()
    {
        
    }

    public void RestartGame()
    {
        StartCoroutine("RestartGameCo");
    }

    public IEnumerator RestartGameCo()
    {
        theScoreManager.scoreIncreasing = false;
        thePlayer.gameObject.SetActive(false);
        yield return new WaitForSeconds(0.5f);
        platformList = FindObjectsOfType<PlatformKiller>();
        for(int i = 0; i < platformList.Length; i++)
        {
            platformList*.gameObject.SetActive(false);*

}

thePlayer.transform.position = playerStartPoint;
platformGenerator.position = platformStartPoint;
thePlayer.gameObject.SetActive(true);

theScoreManager.scoreCount = 0;
theScoreManager.scoreIncreasing = true;
}
}

2

you just need to give the collider object the correct tag. You may only set the tag for the parent of the collider object.

  void OnCollisionEnter2D(Collision2D other)
    {
        if (other.gameObject.tag == "killbox") // error here probably. is the tag really on the object with the collider? maybe its the parent or child.
        {