ArgumentNullException When using Collider2D.OverlapCollider()

The exact error popping up on my unity console is: ArgumentNullException: Value cannot be null.
Parameter name: collider
The exact line the error is on is “col.OverlapCollider(nonPlayer, colliders);”
Which is extremely confusing to me. Also for further information the layer mask NPC is properly defined in earlier code and I have the seem problems even when i keep the contactFilter not having any specific parameters. On top of this the same error occurs even when i set col.OverlapCollider(nonPlayer, colliders); equal to an integer. as in: int h = col.OverlapCollider(nonPlayer, colliders);

public void Attack(Collider2D col, float stagger) //deals with the physical attack of the weapon and it’s interaction with Characters

    ContactFilter2D nonPlayer = new ContactFilter2D()

    nonPlayer.useLayerMask = true;

    List<Collider2D> colliders = new List<Collider2D>();
    col.OverlapCollider(nonPlayer, colliders);
    Debug.Log("hits : " + colliders.Count);
    for(int i = 0; i < colliders.Count; i++)

        colliders*.gameObject.GetComponent<Character>().ReceiveDamage(usedDmgTypes, usedDmgValues, stagger, player.is_FacingRight);*

Debug.Log(“we made it?”);

If this is also helpful the error also gave out this information:
UnityEngine.PhysicsScene2D.OverlapColliderList_Internal (UnityEngine.Collider2D collider, UnityEngine.ContactFilter2D contactFilter, System.Collections.Generic.List1[T] results) (at :0)* *UnityEngine.PhysicsScene2D.OverlapCollider (UnityEngine.Collider2D collider, UnityEngine.ContactFilter2D contactFilter, System.Collections.Generic.List1[T] results) (at :0)
UnityEngine.Collider2D.OverlapCollider (UnityEngine.ContactFilter2D contactFilter, System.Collections.Generic.List`1[T] results) (at :0)
Weapon.Attack (UnityEngine.Collider2D col, System.Single stagger) (at Assets/Scripts/GeneralParents/Weapon.cs:395)

The problem was that the Collider I was trying to call the Overlap collider function from was null. Was simple looking in the wrong place for the error.