title: Entity of type 'AppBundle\Entity\User' for IDs id(155) was not found
body: <p>When I iterate over users of one group (group#users and it's a ManyToOne relationship) to display the users emails, I get this error <code>Entity of type 'AppBundle\Entity\User' for IDs id(155) was not found</code>. However, when I display the user for which the exception is raised I see this:</p>
  
  <pre><code>// In my controller
  dump($groups[0]-&gt;getUser());
  
  // Output
  User {#761 ▼
    +__isInitialized__: false
    #id: 155
    #email: null
    #firstName: null
    #lastName: null
    #roles: null
     …2
  }
  </code></pre>
  
  <p>Besides, this user (whose id equals 155) does exist in my database.</p>
  
  <p><strong>UPDATE 1</strong></p>
  
  <pre><code>public function getByCriteria(array $criteria)
  {
      $qb = $this-&gt;createQueryBuilder('g');
      // ....
  
  
      return $qb
              -&gt;getQuery()
              // This does NOT change anything ?? Isn't this supposed to load related user??
              // http://docs.doctrine-project.org/projects/doctrine-orm/en/latest/reference/dql-doctrine-query-language.html#temporarily-change-fetch-mode-in-dql
              -&gt;setFetchMode('class_namespace', 'user', ClassMetadata::FETCH_EAGER)
              -&gt;getResult();
  }
  </code></pre>