title: What is causing a "Maximum function nesting level" error in Symfony 2.1 and Twig?
body: <p>I have a project on Symfony 2.1. After updating composer components (Gedemo, Symfony core, Doctrine, Twig, etc..) I have the following error:</p>
  
  <pre><code>Fatal error: Maximum function nesting level of '100' reached, aborting! in /var/www/{path}/vendor/twig/twig/lib/Twig/Token.php on line 78
  </code></pre>
  
  <p>I have PHP 5.4. What can cause this error?</p>