Nav Mesh Problem with SetDestination

Why does this work this pops up

public float deathDistance = 0.5f;
public float distanceAway;
public Transform thisObject;
public Transform target;
private NavMeshAgent navComponent;

void Start() 
{
	target = GameObject.FindGameObjectWithTag("Player").transform;
	navComponent = this.gameObject.GetComponent<NavMeshAgent>();
}

void Update() 
{

	float dist = Vector3.Distance(target.position, transform.position);

	if(target)
	{
		navComponent.SetDestination(target.position);
	}

	else
	{
		if(target == null)
		{
			target = this.gameObject.GetComponent<Transform>();
		}
		else
		{
			target = GameObject.FindGameObjectWithTag("Player").transform;
		}
	}
	if (dist <= deathDistance)
	{
		//KILL PLAYER
	}
}

Usually it’s because your NavMeshAgent is inactive, or is not on the NavMesh.