Warning: Undefined variable $file_path in D:\xampp\htdocs\core\init.php on line 29

Fatal error: Uncaught Error: Undefined constant "SITE_DIR" in D:\xampp\htdocs\core\init.php:32 Stack trace: #0 D:\xampp\htdocs\core\start.php(12): require() #1 D:\xampp\htdocs\index.php(25): require('D:\\xampp\\htdocs...') #2 {main} thrown in D:\xampp\htdocs\core\init.php on line 32