OnTriggerEnter2D called twice sometimes when IsTrigger is ON

Questions & Answers
1

I have a game object with only a box collider 2d (IsTrigger is ON) attached to it. I use this to detect ( using OnTriggerEnter2D() ) when player falls on it so that the life count is reduced by 1. But most of the times, it is called twice and life count decrements by 2. After a lot of debugging I found out that this issue only happens when IsTrigger is ON. It doesn’t happen when IsTrigger is OFF. Why is it happening? Is there a problem in my code or is it some sort of unity error?

    private void OnTriggerEnter2D(Collider2D collision)
    {
        if (collision.gameObject.tag == "Deadly")
        {
            lifeCount = lifeCount - 1;
            player.SetActive(false);

            if (lifeCount <= 0)
            {
                DiedPanel.SetActive(true);
            }
            else
            {
               //Some code here to reposition player
               //It is made sure that the player is not positioned on the Deadly.
                player.SetActive(true);
            }
        }
  }
3

So, here is the solution (finally):
I had isTrigger ON on both objects that were colliding. So both of their OnTriggerEnter2D was activated. Although, I have had attached the script on only the player, their was a double decrement. In short:
Do not set both objects’ IsTrigger to TRUE

2

I think it’s because you’re using “player.SetActive()”. Your Player is active, so Trigger is called, next you’re using player.SetActive(false), so GameObject is deactivated and not in collision with your Collider, and “if lifeCount > 0” you’re using SetActive(true), so Player is activated and enters again in collision, OnTriggerEnter is called.