"Particle System has been destroyed but you're still trying to access it."

I’m making a first person shooter and the particle system for the muzzle flash keeps disappearing from the hierarchy every time I run the project. I’ve made sure that the particle system is in the inspector but when I run the project it turns into “Missing(Particle System).” What should I do?

Script(Ignore how messy my code is, this is my first project):

using UnityEngine;
using TMPro;

public class Carbineshoot : MonoBehaviour
{   public AudioSource Shootsound;
    private float rotate = 0;
    public float AKMDamage = 25;
    public Transform casingExitLocation;
    public GameObject casingPrefab;
    public GameObject bullet;
    public AudioSource loadSound;
    //bullet force
    public float shootForce, upwardForce;
    public GameObject player;
    //Gun stats
    public float timeBetweenShooting, spread, reloadTime, timeBetweenShots;
    public int magazineSize, bulletsPerTap;
    public bool allowButtonHold;

    int bulletsLeft, bulletsShot;

    public Rigidbody playerRb;
    public float recoilForce;
    private Vector3 gunTip;
    //public GameObject gunTip;
    public AudioSource audioSource;
    public AudioSource audioSource2;
    public ParticleSystem particles;
    bool shooting, readyToShoot, reloading;
    bool aiming;
    public Camera fpsCam;
    public Transform attackPoint;
    public AudioSource Loading;
    //public AudioSource SlideSound;
    public GameObject muzzleFlash;
    public TextMeshProUGUI ammunitionDisplay;
    public AudioSource Empty_ClickSound;
    //bug fixing :D
    public bool allowInvoke = true;
    public GameObject Pistol;
    public GameObject Glock19;
    public Rigidbody casingRB;
    private void Awake()
 //GameObject varGameObject = GameObject.FindWithTag("Player"); //then disable or enable script/component
// varGameObject.GetComponent<ReloadAKmANim>().enabled = false;
        GetComponent<Animator>().Play("carbineEquip",  0, 0f);
        //make sure magazine is full
        bulletsLeft = magazineSize;
        readyToShoot = true;

    void reloadingfx(){
    void effects(){
         if (Input.GetMouseButtonDown(0))
    private void Update()
        GetComponent<Animator>().Play("carbineReload",  0, 0f);

                GetComponent<Animator>().Play("carbineShoot",  0, 0f);

                GetComponent<Animator>().Play("carbineIdle",  0, 0f);
        if(bulletsLeft <= 0){

        //Set ammo display, if it exists :D
        if (ammunitionDisplay != null)
            ammunitionDisplay.SetText(bulletsLeft / bulletsPerTap + " / " + magazineSize / bulletsPerTap);
    private void MyInput()
    {   if(bulletsLeft == 0&&!reloading){
        if (allowButtonHold) shooting = Input.GetKey(KeyCode.Mouse0);
        else shooting = Input.GetKeyDown(KeyCode.Mouse0);

        if (Input.GetKeyDown(KeyCode.R) && bulletsLeft < magazineSize && !reloading) {
            GetComponent<Animator>().Play("carbineReload",  0, 0f);
        //Reload automatically when trying to shoot without ammo
        if (Input.GetKeyDown(KeyCode.R) && bulletsLeft == 0 && !reloading) {
                   GetComponent<Animator>().Play("carbineReload",  0, 0f);

        if (readyToShoot && shooting && !reloading && bulletsLeft > 0)
            //Set bullets shot to 0
            bulletsShot = 0;


    private void Shoot()
        readyToShoot = false;

        //Find the exact hit position using a raycast
        Ray ray = fpsCam.ViewportPointToRay(new Vector3(0.5f, 0.5f, 0)); //Just a ray through the middle of your current view
        RaycastHit hit;

        //check if ray hits something
        Vector3 targetPoint;
        if (Physics.Raycast(ray, out hit))
            targetPoint = hit.point;
            targetPoint = ray.GetPoint(75); //Just a point far away from the player

        //Calculate direction from attackPoint to targetPoint
        Vector3 directionWithoutSpread = targetPoint - attackPoint.position;

        //Calculate spread
        float x = Random.Range(-spread, spread);
        float y = Random.Range(-spread, spread);

        //Calculate new direction with spread
        Vector3 directionWithSpread = directionWithoutSpread + new Vector3(x, y, 0); //Just add spread to last direction

        //Instantiate bullet/projectile
        GameObject currentBullet = Instantiate(bullet, attackPoint.position, Quaternion.identity); //store instantiated bullet in currentBullet
        //Rotate bullet to shoot direction
        currentBullet.transform.forward = directionWithSpread.normalized;

        //Add forces to bullet
        currentBullet.GetComponent<Rigidbody>().AddForce(directionWithSpread.normalized * shootForce, ForceMode.Impulse);
        currentBullet.GetComponent<Rigidbody>().AddForce(fpsCam.transform.up * upwardForce, ForceMode.Impulse);

        //Instantiate muzzle flash, if you have one
        if (muzzleFlash != null)
            Instantiate(muzzleFlash, attackPoint.position, Quaternion.identity);


        //Invoke resetShot function (if not already invoked), with your timeBetweenShooting
        if (allowInvoke)
            Invoke("ResetShot", timeBetweenShooting);
            allowInvoke = false;

            //Add recoil to player (should only be called once)
            playerRb.AddForce(-directionWithSpread.normalized * recoilForce, ForceMode.Impulse);

        //if more than one bulletsPerTap make sure to repeat shoot function
        if (bulletsShot < bulletsPerTap && bulletsLeft > 0)
            Invoke("Shoot", timeBetweenShots);
    private void ResetShot()
        //Allow shooting and invoking again
        readyToShoot = true;
        allowInvoke = true;
    private void Reload()
    {   Shootsound.Stop();
        reloading = true;
        Invoke("ReloadFinished", reloadTime); //Invoke ReloadFinished function with your reloadTime as delay
        GetComponent<Animator>().Play("carbineReload",  0, 0f);
    private void ReloadFinished()
        //Fill magazine
        bulletsLeft = magazineSize;
        reloading = false;

There is a Destroy call somewhere that removes the particle system. Note that Destroy(ParticleSystem) will remove the particle system component from its gameobject and not the gameobject itself.

I got it to stop disappearing, but the muzzle flash will only play once when the mouse button is down instead of continuously playing. I’ve tried using if(Input.GetButtonDown("Fire1)){ particles.play();} if(Input.GetButtonUp("Fire1)){ particles.stop();}but it will still not work. Any idea what I should do? (Yes, I do have the particle system set to loop.)