07:05:42 Create new PHPExcel object
07:05:42 Set document properties
07:05:42 Set default font
07:05:42 Add some data
07:05:42 Rename worksheet
07:05:42 Write to Excel5 format

Fatal error: Uncaught Error: Call to undefined function mb_strtolower() in /var/www/tsf-audio-bitrate/html/vendor/phpoffice/phpexcel/Classes/PHPExcel/Style/NumberFormat.php:448 Stack trace: #0 [internal function]: PHPExcel_Style_NumberFormat::setLowercaseCallback(Array) #1 /var/www/tsf-audio-bitrate/html/vendor/phpoffice/phpexcel/Classes/PHPExcel/Style/NumberFormat.php(464): preg_replace_callback('/(?:^|")([^"]*)...', Array, 'yyyy-mm-dd') #2 /var/www/tsf-audio-bitrate/html/vendor/phpoffice/phpexcel/Classes/PHPExcel/Style/NumberFormat.php(647): PHPExcel_Style_NumberFormat::formatAsDate(46270.253958333, 'yyyy-mm-dd') #3 /var/www/tsf-audio-bitrate/html/vendor/phpoffice/phpexcel/Classes/PHPExcel/Worksheet.php(738): PHPExcel_Style_NumberFormat::toFormattedString(46270.253958333, 'yyyy-mm-dd') #4 /var/www/tsf-audio-bitrate/html/vendor/phpoffice/phpexcel/Classes/PHPExcel/Writer/Excel5/Worksheet.php(288): PHPExcel_Worksheet->calculateColumnWidths() #5 /var/www/tsf-audio-bitrate/html/vendor/phpoffice/phpexcel/Classes/PHPExcel/Writ in /var/www/tsf-audio-bitrate/html/vendor/phpoffice/phpexcel/Classes/PHPExcel/Style/NumberFormat.php on line 448