问Unity: NullReferenceException:对象引用未设置为对象的实例

EN

using UnityEngine;

public class Collide : MonoBehaviour
{
    public Movement movement;     // A reference to our PlayerMovement script

    // This function runs when we hit another object.
    // We get information about the collision and call it "collisionInfo".
    void OnCollisionEnter(Collision collisionInfo)
    {
        // We check if the object we collided with has a tag called "Obstacle".
        if (collisionInfo.collider.tag == "Obstacle")
        {
            movement.enabled = false;   // Disable the players movement.
            Debug.Log("Coollision occured");
        }
    }
}