Failed to start the session because headers have already been sent by "/var/www/html/vendor/symfony/monolog-bundle/DependencyInjection/Configuration.php" at line 628.

Stack Trace

1. in vendor/symfony/symfony/src/Symfony/Component/HttpFoundation/Session/Storage/NativeSessionStorage.php at line 151 
   148.         }
   150.         if (ini_get('session.use_cookies') && headers_sent($file, $line)) {
   151.             throw new \RuntimeException(sprintf('Failed to start the session because headers have already been sent by "%s" at line %d.', $file, $line));
   152.         }
   154.         // ok to try and start the session
2. at NativeSessionStorage ->start ()
   in vendor/symfony/symfony/src/Symfony/Component/HttpFoundation/Session/Storage/NativeSessionStorage.php at line 293 
   290.         if (!$this->started && $this->saveHandler->isActive()) {
   291.             $this->loadSession();
   292.         } elseif (!$this->started) {
   293.             $this->start();
   294.         }
   296.         return $this->bags[$name];
3. at NativeSessionStorage ->getBag ('attributes')
   in vendor/symfony/symfony/src/Symfony/Component/HttpFoundation/Session/Session.php at line 71 
   68.      */
   69.     public function get($name, $default = null)
   70.     {
   71.         return $this->storage->getBag($this->attributeName)->get($name, $default);
   72.     }
   74.     /**
4. at Session ->get ('locale')
   in src/WebBundle/EventListener/LastRouteListener.php at line 90 
   88.             $this->locale=$cookies->get('locale');
   89.         }else{
   90.             $this->locale=$session->get('locale');
   91.         }
   92. //var_dump( $session->get('locale'));
   93.        // $request = $event->getRequest();
5. at LastRouteListener ->onKernelRequest (object(GetResponseEvent), 'kernel.request', object(TraceableEventDispatcher))
   in vendor/symfony/symfony/src/Symfony/Component/EventDispatcher/Debug/WrappedListener.php at line 61 
   59.         $e = $this->stopwatch->start($this->name, 'event_listener');
   61.         \call_user_func($this->listener, $event, $eventName, $this->dispatcher ?: $dispatcher);
   63.         if ($e->isStarted()) {
   64.             $e->stop();
6. at WrappedListener ->__invoke (object(GetResponseEvent), 'kernel.request', object(ContainerAwareEventDispatcher))
   in vendor/symfony/symfony/src/Symfony/Component/EventDispatcher/EventDispatcher.php at line 184 
   181.             if ($event->isPropagationStopped()) {
   182.                 break;
   183.             }
   184.             \call_user_func($listener, $event, $eventName, $this);
   185.         }
   186.     }
7. at EventDispatcher ->doDispatch (array(object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener)), 'kernel.request', object(GetResponseEvent))
   in vendor/symfony/symfony/src/Symfony/Component/EventDispatcher/EventDispatcher.php at line 46 
   43.         $event->setName($eventName);
   45.         if ($listeners = $this->getListeners($eventName)) {
   46.             $this->doDispatch($listeners, $eventName, $event);
   47.         }
   49.         return $event;
8. at EventDispatcher ->dispatch ('kernel.request', object(GetResponseEvent))
   in vendor/symfony/symfony/src/Symfony/Component/EventDispatcher/Debug/TraceableEventDispatcher.php at line 133 
   131.         $e = $this->stopwatch->start($eventName, 'section');
   133.         $this->dispatcher->dispatch($eventName, $event);
   135.         if ($e->isStarted()) {
   136.             $e->stop();
9. at TraceableEventDispatcher ->dispatch ('kernel.request', object(GetResponseEvent))
   in vendor/symfony/symfony/src/Symfony/Component/HttpKernel/HttpKernel.php at line 116 
   114.         // request
   115.         $event = new GetResponseEvent($this, $request, $type);
   116.         $this->dispatcher->dispatch(KernelEvents::REQUEST, $event);
   118.         if ($event->hasResponse()) {
   119.             return $this->filterResponse($event->getResponse(), $request, $type);
10. at HttpKernel ->handleRaw (object(Request), '1')
    in vendor/symfony/symfony/src/Symfony/Component/HttpKernel/HttpKernel.php at line 57 
    54.         $request->headers->set('X-Php-Ob-Level', ob_get_level());
    56.         try {
    57.             return $this->handleRaw($request, $type);
    58.         } catch (\Exception $e) {
    59.             if ($e instanceof ConflictingHeadersException) {
    60.                 $e = new BadRequestHttpException('The request headers contain conflicting information regarding the origin of this request.', $e);
11. at HttpKernel ->handle (object(Request), '1', true)
    in vendor/symfony/symfony/src/Symfony/Component/HttpKernel/DependencyInjection/ContainerAwareHttpKernel.php at line 67 
    64.         $this->container->set('request', $request, 'request');
    66.         try {
    67.             $response = parent::handle($request, $type, $catch);
    68.         } catch (\Exception $e) {
    69.             $this->container->set('request', null, 'request');
    70.             $this->container->leaveScope('request');
12. at ContainerAwareHttpKernel ->handle (object(Request), '1', true)
    in vendor/symfony/symfony/src/Symfony/Component/HttpKernel/Kernel.php at line 183 
    180.             $this->boot();
    181.         }
    183.         return $this->getHttpKernel()->handle($request, $type, $catch);
    184.     }
    186.     /**
13. at Kernel ->handle (object(Request))
    in web/app.php at line 30 
    27. // When using the HttpCache, you need to call the method in your front controller instead of relying on the configuration parameter
    28. //Request::enableHttpMethodParameterOverride();
    29. $request = Request::createFromGlobals();
    30. $response = $kernel->handle($request);
    31. $response->send();
    32. $kernel->terminate($request, $response);

Stack Trace (Plain Text) 

[1] RuntimeException: Failed to start the session because headers have already been sent by "/var/www/html/vendor/symfony/monolog-bundle/DependencyInjection/Configuration.php" at line 628.
    at n/a
        in /var/www/html/vendor/symfony/symfony/src/Symfony/Component/HttpFoundation/Session/Storage/NativeSessionStorage.php line 151

    at Symfony\Component\HttpFoundation\Session\Storage\NativeSessionStorage->start()
        in /var/www/html/vendor/symfony/symfony/src/Symfony/Component/HttpFoundation/Session/Storage/NativeSessionStorage.php line 293

    at Symfony\Component\HttpFoundation\Session\Storage\NativeSessionStorage->getBag('attributes')
        in /var/www/html/vendor/symfony/symfony/src/Symfony/Component/HttpFoundation/Session/Session.php line 71

    at Symfony\Component\HttpFoundation\Session\Session->get('locale')
        in /var/www/html/src/WebBundle/EventListener/LastRouteListener.php line 90

    at WebBundle\EventListener\LastRouteListener->onKernelRequest(object(GetResponseEvent), 'kernel.request', object(TraceableEventDispatcher))
        in /var/www/html/vendor/symfony/symfony/src/Symfony/Component/EventDispatcher/Debug/WrappedListener.php line 61

    at Symfony\Component\EventDispatcher\Debug\WrappedListener->__invoke(object(GetResponseEvent), 'kernel.request', object(ContainerAwareEventDispatcher))
        in /var/www/html/vendor/symfony/symfony/src/Symfony/Component/EventDispatcher/EventDispatcher.php line 184

    at Symfony\Component\EventDispatcher\EventDispatcher->doDispatch(array(object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener), object(WrappedListener)), 'kernel.request', object(GetResponseEvent))
        in /var/www/html/vendor/symfony/symfony/src/Symfony/Component/EventDispatcher/EventDispatcher.php line 46

    at Symfony\Component\EventDispatcher\EventDispatcher->dispatch('kernel.request', object(GetResponseEvent))
        in /var/www/html/vendor/symfony/symfony/src/Symfony/Component/EventDispatcher/Debug/TraceableEventDispatcher.php line 133

    at Symfony\Component\EventDispatcher\Debug\TraceableEventDispatcher->dispatch('kernel.request', object(GetResponseEvent))
        in /var/www/html/vendor/symfony/symfony/src/Symfony/Component/HttpKernel/HttpKernel.php line 116

    at Symfony\Component\HttpKernel\HttpKernel->handleRaw(object(Request), '1')
        in /var/www/html/vendor/symfony/symfony/src/Symfony/Component/HttpKernel/HttpKernel.php line 57

    at Symfony\Component\HttpKernel\HttpKernel->handle(object(Request), '1', true)
        in /var/www/html/vendor/symfony/symfony/src/Symfony/Component/HttpKernel/DependencyInjection/ContainerAwareHttpKernel.php line 67

    at Symfony\Component\HttpKernel\DependencyInjection\ContainerAwareHttpKernel->handle(object(Request), '1', true)
        in /var/www/html/vendor/symfony/symfony/src/Symfony/Component/HttpKernel/Kernel.php line 183

    at Symfony\Component\HttpKernel\Kernel->handle(object(Request))
        in /var/www/html/web/app.php line 30