find game object with tag error - EXT_FighterAI.cs(45,25): error CS0029: Cannot implicitly convert type `UnityEngine.GameObject[]' to `UnityEngine.GameObject'

trying to find a game object and assign it to a game object public.
EXT_FighterAI.cs(45,25): error CS0029: Cannot implicitly convert type UnityEngine.GameObject[]' to UnityEngine.GameObject’

using UnityEngine;
using System.Collections;

public class EXT_FighterAI : MonoBehaviour {

public GameObject nextWaypoint;

public Transform selectedTarget;
public Transform selectedWaypoint;
public float waypointDistance;

public float maxSpeed;
public float currentSpeed;
public float turnSpeed;
public float shipHealh = 100;
public float AIstance = 1;

//-----------------------------------------------------------------------------------------------------------
// Use this for initialization
void Start () {

}

//-----------------------------------------------------------------------------------------------------------
// Update is called once per frame
void FixedUpdate () {

	// set patrolling AI:
	if (AIstance == 1) {
		patrolingAI ();
	}

}	

//-----------------------------------------------------------------------------------------------------------
void patrolingAI ()	{

	//Always look at waypoint if patrolling.
	Quaternion WantedRotation = Quaternion.LookRotation (nextWaypoint.transform.position - nextWaypoint.transform.position, nextWaypoint.transform.up);

	if (!nextWaypoint) {  // if no waypoint is assigned assign a waypoint.
		//Find and assign a  waypoint find a game object with tag that is also its distance is > X.
		nextWaypoint = GameObject.FindGameObjectsWithTag ("EXT_AI_Waypoint"); 
		waypointDistance = Vector3.Distance(nextWaypoint.transform.position, transform.position);
	}

	//when arive at waypoint, assign new waypoint that is greater distance then 100, so cannot assign the same waypoint.
	//also if first waypoint is to close ind another waypoint.
	if(waypointDistance < 10)	{
		nextWaypoint = GameObject.FindGameObjectsWithTag ("EXT_AI_Waypoint");
	}

}
//-----------------------------------------------------------------------------------------------------------

}

Hi,
you are passing array value to a gameObject.
FindGameobjectsWithTag returns an array of objects which should be passed to array only and not a gameobject.
I hope this solves your problem.