Fatal error: Uncaught Error: Class "PHPExcel_Style_Supervisor" not found in C:\xampp\htdocs\electronica\vendor\phpoffice\phpexcel\Classes\PHPExcel\Style\Fill.php:36 Stack trace: #0 {main} thrown in C:\xampp\htdocs\electronica\vendor\phpoffice\phpexcel\Classes\PHPExcel\Style\Fill.php on line 36