Warning: require(C:/xampp/htdocs/includes/constants.php): failed to open stream: No such file or directory in C:\xampp\htdocs\mainfile.php on line 10

Fatal error: require(): Failed opening required 'C:/xampp/htdocs/includes/constants.php' (include_path='.;C:\xampp\php\PEAR') in C:\xampp\htdocs\mainfile.php on line 10