Error with using System.ID

Unity Engine
1

Hi everyone. I found the next error:

Assets/ScriptsGenerales/22.7.17/dataBaseHandler.cs(3,14): error CS0234: The type or namespace name ID' does not exist in the namespace System’. Are you missing an assembly reference?

In this script:

using UnityEngine;
using System.Collections;
using System.ID;

public class dataBaseHandler : MonoBehaviour {

    public DataBase bd;

    void Start () {
        string datos = File.ReadAllText(Application.dataPath + "/Scripts/cell1.json");
        bd = JsonUtility.FromJson<DataBase>(datos);

    }   

    public Objeto buscarObjetoPorId(int id){
        return bd.baseDatos.Find(objeto => objeto.id == id);
    }
}

Anyone have an idea how to fix it?
Thanks for reading

2

What is System.ID? According to google it doesn’t exist. So you might as well delete line 3 entirely.