opencart前端工作正常，但管理员显示空白页面

I migrated my website from a ftp server to my localhost using MAMP, I exported the database and imported the database to my localhost and then modified my 2 config.php. As a result the frond-end index works well, but I got blank page for my admin index, are there anybody who can help me with it? Thank you in advance.

config.php for the frond:

<?php


    define('HTTP_ROOT', 'http://localhost:8888/uta/');

    define('HTTP_PROJECT_ROOT', HTTP_ROOT);

    define('HTTP_CATALOG', HTTP_ROOT.'');

    //define('HTTP_IMAGE', HTTP_ROOT.'image/');

    define('HTTP_IMAGE', HTTP_ROOT.'image/');

    define('HTTP_ADMIN', HTTP_ROOT.'admin/');



    // HTTPS

    define('HTTPS_SERVER', HTTP_ROOT.'uta/');

    define('HTTPS_IMAGE', HTTP_ROOT.'image/');



    // DIR

    //define('WWW_ROOT', '/home/uta/www/');

    define('WWW_ROOT', '/Applications/MAMP/htdocs/uta/');

    define('DIR_PROJECT_ROOT', WWW_ROOT);

    define('DIR_SYSTEM', WWW_ROOT.'system/');

    define('DIR_LIBRARY', WWW_ROOT.'system/library/');

    define('DIR_SYSTEM_CONFIG', WWW_ROOT.'system/config/');

    define('DIR_SYSTEM_HELPER', WWW_ROOT.'system/helper/');

    define('DIR_SYSTEM_DATABASE', WWW_ROOT.'system/database/');

    define('DIR_SYSTEM_LANGUAGE', WWW_ROOT.'lang/');



    define('DIR_APPLICATION', WWW_ROOT.'catalog/');

    define('DIR_APPLICATION_CONFIG', WWW_ROOT.'catalog/config/');

    define('DIR_APPLICATION_HELPER', WWW_ROOT.'catalog/helper/');

    define('DIR_APPLICATION_LANGUAGE', WWW_ROOT.'catalog/language/');

    define('DIR_APPLICATION_TEMPLATE', WWW_ROOT.'catalog/view/theme/');



    define('DIR_IMAGE', WWW_ROOT.'image/');

    define('DIR_BILLS', WWW_ROOT.'bills/');

    define('DIR_CACHE', WWW_ROOT.'system/cache/');

    define('DIR_LOGS', WWW_ROOT.'system/logs/');

    /**

     * Root of templates directory

     */
    define("TEMPLATES_PDF_DIR", "../../../templates/pdf");


    // DB

    define('DB_DRIVER', 'mysql');

    define('DB_HOSTNAME', 'localhost');

    define('DB_USERNAME', 'xxx');

    define('DB_PASSWORD', 'xxx');

    define('DB_DATABASE', 'xxx');

    define('DB_PREFIX', 'uta_');

    define('SMTP_ADMIN_EMAIL', 'xxx@xxx.com');


    define('APP_ENVIRONMENT', 'FRONT');

    //ini_set('xdebug.var_display_max_depth', '10');
    ?>

config.php for back-end:

<?php

// HTTP



define('HTTP_ROOT', 'http://localhost:8888/uta/');

define('HTTP_PROJECT_ROOT', HTTP_ROOT.'');

define('HTTP_ADMIN', HTTP_ROOT.'admin/');

define('HTTP_SERVER', HTTP_ROOT.'admin/');

define('HTTP_CATALOG', HTTP_ROOT.'');

define('HTTP_IMAGE', HTTP_ROOT.'image/');



// HTTPS

define('HTTPS_SERVER', HTTP_ROOT.'admin/');

define('HTTPS_IMAGE', HTTP_ROOT.'image/');



// DIR



define('WWW_ROOT', '/Applications/MAMP/htdocs/uta/');

define('DIR_PROJECT_ROOT', WWW_ROOT.'');

define('DIR_SYSTEM', WWW_ROOT.'system/');

define('DIR_LIBRARY', WWW_ROOT.'system/library/');

define('DIR_SYSTEM_CONFIG', WWW_ROOT.'system/config/');

define('DIR_SYSTEM_HELPER', WWW_ROOT.'system/helper/');

define('DIR_SYSTEM_DATABASE', WWW_ROOT.'system/database/');

define('DIR_SYSTEM_LANGUAGE', WWW_ROOT.'system/language/');



define('DIR_APPLICATION', WWW_ROOT.'admin/');

define('DIR_APPLICATION_CONFIG', WWW_ROOT.'admin/config/');

define('DIR_APPLICATION_HELPER', WWW_ROOT.'admin/helper/');

define('DIR_APPLICATION_LANGUAGE', WWW_ROOT.'admin/language/');

define('DIR_APPLICATION_TEMPLATE', WWW_ROOT.'admin/view/template/');



define('DIR_IMAGE', WWW_ROOT.'image/');

define('DIR_CACHE', WWW_ROOT.'system/cache/');

define('DIR_LOGS', WWW_ROOT.'system/logs/');



define('DIR_LANGUAGE', WWW_ROOT.'admin/language/');

define('DIR_LANGUAGE_CATALOG', WWW_ROOT.'catalog/language/');

//Template generation PDF

define("TEMPLATES_PDF_DIR", "../../../templates/pdf");

// DB

define('DB_DRIVER', 'mysql');

define('DB_HOSTNAME', 'localhost');

define('DB_USERNAME', 'xxx');

define('DB_PASSWORD', 'xxx');

define('DB_DATABASE', 'xxx');

define('DB_PREFIX', 'xxx_');

define('SMTP_ADMIN_EMAIL', 'xxx@xxx.com');

define('APP_ENVIRONMENT', 'BACK');



?>