ReflectionException：Property $ id不存在

I've changed the primary key of an entity, but now I'm getting back this error:

ReflectionException Property DnD\\ApiBundle\\Entity\\Agent::$id does not exist

My entity is this:

<?php

namespace DnD\ApiBundle\Entity;

use Doctrine\ORM\Mapping as ORM;
use JMS\Serializer\Annotation\Groups;
use Doctrine\ORM\Mapping\Id;
use Doctrine\ORM\Mapping\Column;

/**
 * Agent
 *
 * @ORM\Table()
 * @ORM\Entity(repositoryClass="DnD\ApiBundle\Repository\AgentRepository")
 */
class Agent
{

  /**
   * @var string
   *
   * @Groups({"list", "details"})
   * @Id
   * @Column(type="string", length=255)
   */
  private $agentId;

  ...

I've already clear doctrine cache, but the error persists. Why is this happening.

Thanks!

clearing cache by app/console its not enough, remove cache folder completely, it works for me