MAGETWO-70133: 404 page for not allowed magento config sections

Author: rganin

app/code/Magento/Config/Controller/Adminhtml/System/AbstractConfig.php

@@ -28,19 +28,18 @@ abstract class AbstractConfig extends \Magento\Backend\App\AbstractAction
 
     /**
      * @deprecated
-     * @var ConfigSectionChecker
      */
     protected $_sectionChecker;
 
     /**
      * @param \Magento\Backend\App\Action\Context $context
      * @param \Magento\Config\Model\Config\Structure $configStructure
-     * @param ConfigSectionChecker $sectionChecker
+     * @param $sectionChecker - deprecated
      */
     public function __construct(
         \Magento\Backend\App\Action\Context $context,
         \Magento\Config\Model\Config\Structure $configStructure,
-        ConfigSectionChecker $sectionChecker
+        $sectionChecker
     ) {
         parent::__construct($context);
         $this->_configStructure = $configStructure;
@@ -60,6 +59,7 @@ public function dispatch(\Magento\Framework\App\RequestInterface $request)
                 $request->setParam('section', $this->_configStructure->getFirstSection()->getId());
             } catch (LocalizedException $e) {
                 /** If visible section not found need to show only config index page without sections if it allow. */
+                $this->messageManager->addWarningMessage($e->getMessage());
             }
         }
         return parent::dispatch($request);

app/code/Magento/Config/Controller/Adminhtml/System/ConfigSectionChecker.php

@@ -9,7 +9,7 @@
 use Magento\Framework\Exception\NotFoundException;
 
 /**
- * @deprecated Due of not use.
+ * @deprecated - unused class.
  * @see \Magento\Config\Model\Config\Structure\Element\Section::isAllowed()
  */
 class ConfigSectionChecker