fix: error on InitializeIfNeeded

close #264

Scripts/UIParticle.cs

@@ -480,6 +480,7 @@ protected override void OnDidApplyAnimationProperties()
 
  private void InitializeIfNeeded()
  {
+ if (!this) return;
  if (enabled && m_IsTrail)
  {
  UnityEngine.Debug.LogWarningFormat(this, "[UIParticle] The UIParticle component should be removed: {0}\nReason: UIParticle for trails is no longer needed.", name);