My onTriggerEnter is not called

Hello everyone, am new to unity, am working on a project. I discovered that my onTriggerEnter doesn’t work when my shell(bullet) enters the trigger zone. I added collider to my shell, i also checked is a trigger and the cube am shooting at also has a box collider. I have seen solutions but none of them worked for me. Can someone assist me with this.

private void OnTriggerEnter(Collider other)
	//	Rigidbody targetRigidbody = GetComponent<Rigidbody> ();
	//	targetRigidbody.AddForce (transform.forward * 100);
	    m_ExplosionParticles.transform.parent = null;
		m_ExplosionParticles.Play ();
		m_ExplosionAudio.Play ();
		Destroy (m_ExplosionParticles.gameObject, m_ExplosionParticles.duration);
		Destroy (gameObject);

		if(m_ExplosionParticles.isPlaying) m_ExplosionParticles.Stop();

	  //   playerHealth.TakeDamage (damage);
			Debug.Log ("trigger is working");

@saud_ahmed020 the cube and shell has rigidbody and colliders