Update LocalArticleManager.php

php/controller/showCategory-controller.php

@@ -9,12 +9,12 @@ if (isset($_GET["category"]) && !empty($_GET["category"]) && articleCategoryVali
         $articles = $articleManager->getArticlesByCategory($category);
     } catch (Exception $e) {
         $_SESSION["message"] = "internal_error";
-        header("location: ../../index.php");
+        include_once "content/404.php";
         exit();
     }
 }else{
     $_SESSION["message"] = "invalid_category";
-    header("location: ../../index.php");
+    include_once "content/404.php";
     exit();
 }
 ?>

php/model/LocalArticleManager.php

@@ -200,7 +200,7 @@ class LocalArticleManager implements ArticleManagerDAO {
 
     return $filteredArticles;
     }
-    
+
     public function getArticlesByCategory($category)
     {
         $articles = $this->getAllArticles();