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