title: OnParticleCollision doesn't get triggered in Unity 2018.2
body: <p>After loading my Unity 2018.1.1 project in Untiy 2018.2.2, the OnParticleCollision method doesn't get triggered at all. Everything worked fine in Unity 2018.1.1.
  <br />
  There's no official information about updating particle collisions whatsoever.</p>
  
  <p>Here's my C# code for the Enemy script.
  <br />
  The Player GameObject has a particle system that serves as a weapon + the Collision module is enabled and is properly set up to collide with the Enemies layer.</p>
  
  <pre><code>using System.Collections;
  using System.Collections.Generic;
  using UnityEngine;
  
  public class Enemy : MonoBehaviour
  {
      // Enemy health
      private int health = 100;
  
      // !!! Doesn't get triggered at all !!!
      // When the player's weapon hits the Enemy
      private void OnParticleCollision(GameObject other)
      {
          Debug.Log(other.tag);
  
          if (other.tag == "Weapon")
          {
              // Reduce health
              health -= 50;
              if (health &lt;= 0)
              {
                  // Disable the Enemy that was just killed
                  gameObject.SetActive(false);
              }
          }
      }
  }
  </code></pre>