title: Symfony 3.1.5 Warning: SessionHandler::read(): Session data file is not created by your uid
body: <p>I'm running Symfony 3.1.5 on a Ubuntu 14.04, PHP 7.1 and Apache 2.4.23 stack managed by Vagrant 1.8.6/VirtualBox 5.1.6. I'm trying to use a simple controller I've made to render a response on my frontend:</p>
  
  <pre><code>&lt;?php
  
  namespace AppBundle\Controller;
  
  use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
  use Symfony\Component\BrowserKit\Response;
  
  class LandingController {
      /**
       * @Route("/", name="homepage")
       */
      public function showAction(){
          return new Response('This is the landing page!');
      }
  }
  </code></pre>
  
  <p>When I attempt to access my Symfony frontend via <code>/app_dev.php</code> I see:</p>
  
  <p><code>Warning: SessionHandler::read(): Session data file is not created by your uid
  500 Internal Server Error - ContextErrorException</code></p>
  
  <p>My Apache log reads:</p>
  
  <p><code>CRITICAL - Uncaught PHP Exception Symfony\Component\Debug\Exception\ContextErrorException: "Warning: SessionHandler::read(): Session data file is not created by your uid" at /var/www/conan/var/cache/dev/classes.php line 366</code></p>
  
  <p>The Symfony dev log reads:</p>
  
  <p><code>==&gt; /var/www/conan/var/logs/dev.log &lt;==
  [2016-10-11 14:23:04] request.INFO: Matched route "{route}". {"route":"homepage","route_parameters":{"_controller":"AppBundle\\Controller\\LandingController::showAction","_route":"homepage"},"request_uri":"http://conan.dev/app_dev.php/","method":"GET"} []
  [2016-10-11 14:23:04] request.CRITICAL: Uncaught PHP Exception Symfony\Component\Debug\Exception\ContextErrorException: "Warning: SessionHandler::read(): Session data file is not created by your uid" at /var/www/conan/var/cache/dev/classes.php line 366 {"exception":"[object] (Symfony\\Component\\Debug\\Exception\\ContextErrorException(code: 0): Warning: SessionHandler::read(): Session data file is not created by your uid at /var/www/conan/var/cache/dev/classes.php:366)"} []
  </code></p>
  
  <p>Seeing as this appears to be a session related issue, I've referred to the Symfony documentation for <a href="https://symfony.com/doc/current/components/http_foundation/sessions.html">Session Management</a>. It states: </p>
  
  <blockquote>
    <p>Symfony sessions are incompatible with php.ini directive session.auto_start = 1 This directive should be turned off in php.ini, in the webserver directives or in .htaccess.</p>
  </blockquote>
  
  <p><code>session.auto_start = 0</code> in my <code>php.ini</code> and the file is owned by user and group <code>root</code>:</p>
  
  <p><code>$ ls -lta /etc/php/7.1/fpm/php.ini
  -rw-r--r-- 1 root root 70584 Sep 30 07:29 /etc/php/7.1/fpm/php.ini</code></p>
  
  <p>I've tried creating an <code>.htaccess</code> (which I placed in my <code>DocumentRoot</code>) per the instructions in the Symfony documentation, but the error persists.</p>
  
  <p>I've searched several threads and questions for a solution but have not landed on anything. Any ideas what is causing this?</p>