title: Symfony4 Expected String but got String
body: <p>I have this error everywhere in my Controller where I "render" or I access a variable through a <code>getParameter</code>:</p>
  
  <blockquote>
    <p><code>expected "\Symfony\Bundle\FrameworkBundle\Controller\string" got string</code></p>
  </blockquote>
  
  <p>What's wrong?</p>