I just made a quick Hello World php file and have it stored in my file path /opt/lampp/htdocs. However when I go to the URL localhost/hello.php, I get "404 Not Found The requested URL /first.php was not found on this server. Apache/2.2.14 (Ubuntu) Server at localhost Port 80. " As far as I know I did everything right, so could it be a problem with XAMPP? I'm really new at this, thank you.