Symfony error: Class 'Symfony\Component\HttpKernel\Kernel' not found

Question

After upgrading from Symfony 3.1 to 3.2 I get this error message :

Fatal error: Class 'Symfony\Component\HttpKernel\Kernel' not found in /var/www/html/HeliosBlog/app/AppKernel.php on line 6

Here's what my app/autoload.php looks like:

<?php

use Doctrine\Common\Annotations\AnnotationRegistry;

if (!$loader = @include __DIR__.'/../vendor/autoload.php') {

    $message = <<< EOF

EOF;

    if (PHP_SAPI === 'cli') {
        $message = strip_tags($message);
    }

    die($message);
}

// intl
if (!function_exists('intl_get_error_code')) {
    require_once __DIR__.'/../vendor/symfony/symfony/src/Symfony/Component/Locale/Resources/stubs/functions.php';

    $loader->add('', __DIR__.'/../vendor/symfony/symfony/src/Symfony/Component/Locale/Resources/stubs');
}

AnnotationRegistry::registerLoader(array($loader, 'loadClass'));

return $loader;

Here's what my app_dev.php file looks like:

<?php

use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\Debug\Debug;

if (isset($_SERVER['HTTP_CLIENT_IP'])
    || isset($_SERVER['HTTP_X_FORWARDED_FOR'])
    || !(in_array(@$_SERVER['REMOTE_ADDR'], array(
            '127.0.0.1',
            'fe80::1', '::1')) || php_sapi_name() === 'cli-server')
) {
    header('HTTP/1.0 403 Forbidden');
    exit('You are not allowed to access this file. Check '.basename(__FILE__).' for more information.');
}

$loader = require __DIR__.'/../app/autoload.php';
Debug::enable();

require_once __DIR__.'/../app/AppKernel.php';

$kernel = new AppKernel('dev', true);
//$kernel->loadClassCache();
$request = Request::createFromGlobals();
$response = $kernel->handle($request);
$response->send();
$kernel->terminate($request, $response);

And here's what my AppKernel.php looks like:

<?php

use Symfony\Component\HttpKernel\Kernel;
use Symfony\Component\Config\Loader\LoaderInterface;

class AppKernel extends Kernel
{

    public function registerBundles()
    {
        $bundles = array(
            new Symfony\Bundle\FrameworkBundle\FrameworkBundle(),
            new Symfony\Bundle\SecurityBundle\SecurityBundle(),
            new Symfony\Bundle\TwigBundle\TwigBundle(),
            new Symfony\Bundle\MonologBundle\MonologBundle(),
            new Symfony\Bundle\SwiftmailerBundle\SwiftmailerBundle(),
            new Doctrine\Bundle\DoctrineBundle\DoctrineBundle(),
            new Sensio\Bundle\FrameworkExtraBundle\SensioFrameworkExtraBundle(),
            new JMS\AopBundle\JMSAopBundle(),
            new JMS\DiExtraBundle\JMSDiExtraBundle($this),
            new JMS\SecurityExtraBundle\JMSSecurityExtraBundle(),
            new JMS\SerializerBundle\JMSSerializerBundle(),
            new Helios\BlogBundle\HeliosBlogBundle(),
            new Stof\DoctrineExtensionsBundle\StofDoctrineExtensionsBundle(),
            new Helios\UserBundle\HeliosUserBundle(),
            new FOS\UserBundle\FOSUserBundle(),
            new FOS\ElasticaBundle\FOSElasticaBundle(),
            new Knp\Bundle\MarkdownBundle\KnpMarkdownBundle(),
            new Helios\ManagerBundle\HeliosManagerBundle(),
            new FOS\JsRoutingBundle\FOSJsRoutingBundle(),
            //new Avalanche\Bundle\ImagineBundle\AvalancheImagineBundle(),
            new Oneup\UploaderBundle\OneupUploaderBundle(),
            new Gregwar\CaptchaBundle\GregwarCaptchaBundle(),
            new Sonata\AdminBundle\SonataAdminBundle(),
            new Sonata\DoctrineORMAdminBundle\SonataDoctrineORMAdminBundle(),
            new Sonata\BlockBundle\SonataBlockBundle(),
            new Sonata\CoreBundle\SonataCoreBundle(),
            new Knp\Bundle\MenuBundle\KnpMenuBundle(),
            new HWI\Bundle\OAuthBundle\HWIOAuthBundle(),
            new Ivory\CKEditorBundle\IvoryCKEditorBundle(),
        );

        if (in_array($this->getEnvironment(), array('dev', 'test'))) {
            $bundles[] = new Symfony\Bundle\WebProfilerBundle\WebProfilerBundle();
            $bundles[] = new Sensio\Bundle\DistributionBundle\SensioDistributionBundle();
            $bundles[] = new Sensio\Bundle\GeneratorBundle\SensioGeneratorBundle();

            $bundles[] = new Doctrine\Bundle\FixturesBundle\DoctrineFixturesBundle();
            $bundles[] = new CoreSphere\ConsoleBundle\CoreSphereConsoleBundle();
        }

        return $bundles;
    }

    public function registerContainerConfiguration(LoaderInterface $loader)
    {
        $loader->load(__DIR__.'/config/config_'.$this->getEnvironment().'.yml');
    }
}

Already tried removing the vendor folder and doing a composer install.

Any ideas?

Answer 1

I was able to solve it by simply adding

require_once __DIR__.'/autoload.php';

to app/console before

require_once __DIR__ . '/AppKernel.php';` 

Answer 2

Ran into the same error. Found that the bootstrap.php.cache was unaware of the Kernel class. This happened due the Sensio Distibution bundle having an update. For this I posted an issue which can be found here: https://github.com/sensiolabs/SensioDistributionBundle/issues/302

I hope this helps others as well.