How to fix class is not a valid entity or mapped super class?

So I'm trying to follow symfony2's tutorial on doctrine for my own website and modeling my User entity after their Product one.

Also, before anyone marks this a duplicate, I have already tried the solutions given in numerous other questions with no luck:

• Not a valid entity or mapped super class
• Doctrine class is not a valid entity or mapped super class
• Symfony/Doctrine: Class is not a valid entity or mapped super class
• symfony2 is not a valid entity or mapped super class
• Symfony/Doctrine: Class is not a valid entity or mapped super class
• "Class XXX is not a valid entity or mapped super class" after moving the class in the filesystem

and the list goes on

I have my entity class:

<?php
    namespace MySite\MyBundle\Entity;

    use Doctrine\ORM\Mapping as ORM;

    /**
     * @ORM\Entity
     * @ORM\Table(name="user")
     */
    class User
    {
        /**
         * @ORM\Column(type="integer")
         * @ORM\Id
         * @ORM\GeneratedValue(strategy="AUTO")
         */
        protected $id;

        /**
         * @ORM\Column(type="string", length=100)
         */
        protected $name;

        /**
         * @ORM\Column(type="string", length=64)
         */
        protected $password;
    }
?>

Now, I'm running the command:

$ php app/console doctrine:generate:entities MySite/MyBundle/Entity/User

to generate the accessor methods. However, when I do this, I get the error:

[Doctrine\ORM\Mapping\MappingException]
Class "MySite\MyBundle\Entity\User" is not a valid entity or mapped super class.