Notice: Use of undefined constant PHPEXCEL_ROOT - assumed 'PHPEXCEL_ROOT' in C:\Pharmavitale\Fichiers\PHP\Prog\ressources\PHPExcel\Autoloader.php on line 0

Fatal error: Class 'PHPExcel_Shared_String' not found in C:\Pharmavitale\Fichiers\PHP\Prog\ressources\PHPExcel\Autoloader.php on line 0