title: Why Symfony 3 can't open a _wdt/wdt url?
body: <p>I have installed Symfony 3 and configure a nginx according documentation <a href="http://symfony.com/doc/current/cookbook/configuration/web_server_configuration.html" rel="nofollow">http://symfony.com/doc/current/cookbook/configuration/web_server_configuration.html</a>. I open the app_dev.php and Symfony sends ajax request to /_wdt, but gets 404 error.
  I checked routes:</p>
  
  <pre><code>  Name                       Method   Scheme   Host   Path
   -------------------------- -------- -------- ------ -----------------------------------
    _wdt                       ANY      ANY      ANY    /_wdt/{token}
    _profiler_home             ANY      ANY      ANY    /_profiler/
    _profiler_search           ANY      ANY      ANY    /_profiler/search
    _profiler_search_bar       ANY      ANY      ANY    /_profiler/search_bar
    _profiler_info             ANY      ANY      ANY    /_profiler/info/{about}
    _profiler_phpinfo          ANY      ANY      ANY    /_profiler/phpinfo
    _profiler_search_results   ANY      ANY      ANY    /_profiler/{token}/search/results
    _profiler                  ANY      ANY      ANY    /_profiler/{token}
    _profiler_router           ANY      ANY      ANY    /_profiler/{token}/router
    _profiler_exception        ANY      ANY      ANY    /_profiler/{token}/exception
    _profiler_exception_css    ANY      ANY      ANY    /_profiler/{token}/exception.css
    _twig_error_test           ANY      ANY      ANY    /_error/{code}.{_format}
    homepage                   ANY      ANY      ANY    /
   -------------------------- -------- -------- ------ -----------------------------------
  </code></pre>
  
  <p>The _wdt route exist. Why it doesn't work?</p>