Fatal error: Uncaught TypeError: call_user_func_array(): Argument #1 ($callback) must be a valid callback, class UserController does not have a method "index" in /home/learncodes/htdocs/learncodes.online/app/core/App.php:30 Stack trace: #0 /home/learncodes/htdocs/learncodes.online/public/index.php(9): App->__construct() #1 /home/learncodes/htdocs/learncodes.online/index.php(49): require_once('...') #2 {main} thrown in /home/learncodes/htdocs/learncodes.online/app/core/App.php on line 30