Fatal error: Uncaught Error: Interface "PHPExcel_Writer_IWriter" not found in E:\www\API\mod_oth\lib\PHPExcel-1.8\Classes\PHPExcel\Writer\Abstract.php:28 Stack trace: #0 {main} thrown in E:\www\API\mod_oth\lib\PHPExcel-1.8\Classes\PHPExcel\Writer\Abstract.php on line 28