Fatal error: Uncaught Error: Call to undefined function Magento\Framework\Serialize\Serializer\utf8ize() in /var/www/html/vendor/magento/framework/Serialize/Serializer/Json.php:24 Stack trace: #0 /var/www/html/vendor/magento/framework/ObjectManager/Config/Config.php(292): Magento\Framework\Serialize\Serializer\Json->serialize() #1 /var/www/html/vendor/magento/framework/ObjectManager/ObjectManager.php(84): Magento\Framework\ObjectManager\Config\Config->extend() #2 /var/www/html/vendor/magento/framework/App/ObjectManager/Environment/Developer.php(79): Magento\Framework\ObjectManager\ObjectManager->configure() #3 /var/www/html/vendor/magento/framework/App/ObjectManagerFactory.php(191): Magento\Framework\App\ObjectManager\Environment\Developer->configureObjectManager() #4 /var/www/html/vendor/magento/framework/App/Bootstrap.php(212): Magento\Framework\App\ObjectManagerFactory->create() #5 /var/www/html/vendor/magento/framework/App/Bootstrap.php(127): Magento\Framework\App\Bootstrap->__construct() #6 /var/www/html/pub/index.php(27): Magento\Framework\App\Bootstrap::create() #7 {main} thrown in /var/www/html/vendor/magento/framework/Serialize/Serializer/Json.php on line 24