[6082asil]

using UnityEngine;
using System.Collections;

[RequireComponent (typeof (Rigidbody))]

public class spacebarImpulse : MonoBehaviour {



	void Start () {
		
	}

	void Update () {
		if(Input.GetKeyDown(KeyCode.Space)) {
			GameObject.Find("astar").GetComponent<AstarPath>().enabled = !GameObject.Find("astar").GetComponent<AstarPath>().enabled;
			GameObject[] Enemies = GameObject.FindGameObjectsWithTag("enemy");
			foreach (GameObject enemy in Enemies) {
				GetComponent<AIFollow>().enabled = !GetComponent<AIFollow>().enabled;
				rigidbody.AddExplosionForce(10,transform.position,5);
			}
		}
	}
}

После компиляции:
Assets/Handmade/Enemy/spacebarImpulse.cs(18,45): warning CS0219: The variable `enemy' is assigned but its value is never used

При нажатии на пробел:
NullReferenceException: Object reference not set to an instance of an object
spacebarImpulse.Update () (at Assets/Handmade/Enemy/spacebarImpulse.cs:19)