Magento 2 HTTP error 500 on categories after compilation

Question

I am working on a Magento 2.1 website for one of my clients. When running setup:di:compile, my Magento files are successfully compiled without errors.

When I open the frontend of my website, my homepages and other CMS pages work fine. But when I go to a category page, like /shop, I get a HTTP error 500.

The strange thing is, once I delete the var/di folder, this error disappears and I can visit all my pages and categories, but my website becomes extremely slow (like 11 seconds to load a simple page).

So what could cause the HTTP 500 error after compiling and what could be wrong with my var/di folder?

EDIT: after turning on PHP error reporting, the following error is shown when visiting category pages (not homepage and CMS pages):

Fatal error: Uncaught TypeError: Argument 1 passed to Plazathemes\LayeredNavigation\Controller\Category\View::__construct() must be an instance of Magento\Framework\App\Action\Context, instance of Magento\Framework\ObjectManager\ObjectManager given, called in vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php on line 93 and defined in app/code/Plazathemes/Layerednavigation/Controller/Category/View.php:27
Stack trace: #0 vendor/magento/framework/ObjectManager/Factory/AbstractFactory.php(93): Plazathemes\LayeredNavigation\Controller\Category\View->__construct(Object(Magento\Framework\ObjectManager\ObjectManager))
#1 vendor/magento/framework/ObjectManager/Factory/Compiled.php(88): Magento\Framework\ObjectManager\Factory\AbstractFactory->createObject('Plazathemes\Lay...', Array)
#2 vendor/magento/framework/ObjectManager/ObjectManager.php(57): Magento\F in app/code/Plazathemes/Layerednavigation/Controller/Category/View.php on line 27

The file app/code/Plazathemes/Layerednavigation/Controller/Category/View.phplooks like this:

 namespace Plazathemes\LayeredNavigation\Controller\Category;
use Magento\Catalog\Api\CategoryRepositoryInterface;
use Magento\Catalog\Model\Layer\Resolver;
use Magento\Framework\Exception\NoSuchEntityException;
use Magento\Framework\View\Result\PageFactory;
/**
 * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
 */
class View extends \Magento\Catalog\Controller\Category\View
{
 /**
 * Catalog Layer Resolver
 *
 * @var Resolver
 */
 private $layerResolver;
 public function __construct(
 \Magento\Framework\App\Action\Context $context,
 \Magento\Catalog\Model\Design $catalogDesign,
 \Magento\Catalog\Model\Session $catalogSession,
 \Magento\Framework\Registry $coreRegistry,
 \Magento\Store\Model\StoreManagerInterface $storeManager,
 \Magento\CatalogUrlRewrite\Model\CategoryUrlPathGenerator $categoryUrlPathGenerator,
 PageFactory $resultPageFactory,
 \Magento\Framework\Controller\Result\ForwardFactory $resultForwardFactory,
 Resolver $layerResolver,
 CategoryRepositoryInterface $categoryRepository
 )
 {
 parent::__construct($context, $catalogDesign, $catalogSession, $coreRegistry, $storeManager, $categoryUrlPathGenerator, $resultPageFactory, $resultForwardFactory, $layerResolver, $categoryRepository);
 $this->layerResolver = $layerResolver;
 }
 public function execute()
 {
 $layer_action = $this->getRequest()->getParam('layer_action');
 if($layer_action == 1) {
 if ($this->_request->getParam(\Magento\Framework\App\ActionInterface::PARAM_NAME_URL_ENCODED)) {
 return $this->resultRedirectFactory->create()->setUrl($this->_redirect->getRedirectUrl());
 }
 $category = $this->_initCategory();
 if ($category) {
 $this->layerResolver->create(Resolver::CATALOG_LAYER_CATEGORY);
 $settings = $this->_catalogDesign->getDesignSettings($category);
 if ($settings->getCustomDesign()) {
 $this->_catalogDesign->applyCustomDesign($settings->getCustomDesign());
 }
 $this->_catalogSession->setLastViewedCategoryId($category->getId());
 $page = $this->resultPageFactory->create();
 if ($settings->getPageLayout()) {
 $page->getConfig()->setPageLayout($settings->getPageLayout());
 }
 if ($category->getIsAnchor()) {
 $type = $category->hasChildren() ? 'layered' : 'layered_without_children';
 } else {
 $type = $category->hasChildren() ? 'default' : 'default_without_children';
 }
 if (!$category->hasChildren()) {
 $parentType = strtok($type, '_');
 $page->addPageLayoutHandles(['type' => $parentType]);
 }
 $page->addPageLayoutHandles(['type' => $type, 'id' => $category->getId()]);
 $layoutUpdates = $settings->getLayoutUpdates();
 if ($layoutUpdates && is_array($layoutUpdates)) {
 foreach ($layoutUpdates as $layoutUpdate) {
 $page->addUpdate($layoutUpdate);
 }
 }
 $product_list = $page->getLayout()->getBlock('category.products.list')->toHtml();
 if($page->getLayout()->getBlock('catalog.leftnav')) {
 $leftLayer = $page->getLayout()->getBlock('catalog.leftnav')->toHtml();
 } else {
 $leftLayer = false;
 }
 $data['leftLayer'] = $leftLayer;
 $data['productlist'] = $product_list;
 $this->getResponse()->representJson(
 $this->_objectManager->get('Magento\Framework\Json\Helper\Data')->jsonEncode($data)
 );
 } elseif (!$this->getResponse()->isRedirect()) {
 return $this->resultForwardFactory->create()->forward('noroute');
 }
 } else {
 return parent::execute();
 }
 }
}

I have found this issue on GitHub (https://github.com/magento/magento2/issues/4896) which is very similar to mine, but I cannot find how to adapt my code.

• Moshe Shperling: Please be more specific with 500 error. Look for some details in magento logs or server php logs
• Khoa Truong: How about your issue?
• Senne Vandenputte: @KhoaTruongDinh I edited my question and added the errors I get.
• Khoa Truong: You should check the arguments passed to the construct method. Which is your application mode? You should read more here: github.com/magento/magento2/issues/4896. Can you post your app/code/Plazathemes/Layerednavigation/Controller/Category/View.php?
• Senne Vandenputte: @KhoaTruongDinh Magento is currently in production mode. I checked the issue there and it is very similar, but I cannot find how to adapt my own code. I added the complete view.php file to my question.

Answer 1

Just in case someone else comes across this, I finally got it to work.

There seemed to be a problem with two files inside the var/di folder: frontend.ser and global.ser. Once these files were deleted, everything works just fine and the internal server error disappears.

I am still not sure what caused these files to become a problem, but at least just deleting them got me going again and fixed the issue.

Hopefully this solution will work for others experiencing this same problem.

• Ramki: Is this better way then why we need to run di compile

Answer 2

1) You should check your current application mode:

php bin/magento deploy:mode:show

If the current mode is developer mode. You shouldn't run di compile. Di compile is used for production mode.

2) 500 Error is a server error. You should enable Display Errors in app/bootstrap.php or index.php file to see the error.

ini_set('display_errors', -1); // Remember to set -1

NOTE: should enable cache and check the permission properly.

• Senne Vandenputte: I edited my question and added the errors I get.