Warning: Constant WPLANG already defined in D:\xampp\htdocs\mengzhu\wp-config.php on line 80

Fatal error: Uncaught Error: Undefined constant "‘WP_DEBUG’" in D:\xampp\htdocs\mengzhu\wp-config.php:88 Stack trace: #0 D:\xampp\htdocs\mengzhu\wp-load.php(50): require_once() #1 D:\xampp\htdocs\mengzhu\wp-blog-header.php(13): require_once('D:\\xampp\\htdocs...') #2 D:\xampp\htdocs\mengzhu\index.php(17): require('D:\\xampp\\htdocs...') #3 {main} thrown in D:\xampp\htdocs\mengzhu\wp-config.php on line 88