Fatal error: Uncaught Error: Undefined constant "PHPEXCEL_ROOT" in E:\www\API\mod_oth\lib\PHPExcel-1.8\Classes\PHPExcel\Shared\trend\linearBestFitClass.php:3 Stack trace: #0 {main} thrown in E:\www\API\mod_oth\lib\PHPExcel-1.8\Classes\PHPExcel\Shared\trend\linearBestFitClass.php on line 3