Fatal error: Uncaught Error: Undefined constant "ROOT_DIR" in C:\xampp\htdocs\sisprestamo15\lib\config\autoload.php:6 Stack trace: #0 C:\xampp\htdocs\sisprestamo15\templates\header.php(1): include_once() #1 C:\xampp\htdocs\sisprestamo15\index.php(1): include_once('C:\\xampp\\htdocs...') #2 {main} thrown in C:\xampp\htdocs\sisprestamo15\lib\config\autoload.php on line 6