PHP Excel 2007- cannot write to excel file - php

Question

Whenever I try to run this function and generate excel 2007 file, i get this error of no-response.
But, whenever I try to run this code for Excel5, the file generates. I have tried every other option, but this simply doesnt seem to work.
public function get_excel2(){
//load PHPExcel library
$this->load->library('Excel');
// Create new PHPExcel object
$objPHPExcel = new PHPExcel();
// Set document properties
$objPHPExcel->getProperties()->setCreator("me")
->setLastModifiedBy("myself")
->setTitle("Office 2007 XLSX Test Document")
->setSubject("Office 2007 XLSX Test Document")
->setDescription("Test document for Office 2007 XLSX, generated by PHP classes.")
->setKeywords("office 2007 openxml php")
->setCategory("Test result file");
// Add some data
$objPHPExcel->setActiveSheetIndex(0)
->setCellValue('A1', 'Hello')
->setCellValue('B2', 'world!')
->setCellValue('C1', 'bonjour')
->setCellValue('C2', 'monde')
->setCellValue('A4', 'testing');
// Rename worksheet (worksheet, not filename)
$objPHPExcel->getActiveSheet()->setTitle('createdUsingPHPExcel');
// Set active sheet index to the first sheet, so Excel opens this as the first sheet
$objPHPExcel->setActiveSheetIndex(0);
// Redirect output to a client’s web browser (Excel2007)
//clean the output buffer
ob_end_clean();
//this is the header given from PHPExcel examples. but the output seems somewhat corrupted in some cases.
//header('Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet');
//so, we use this header instead.
header('Content-type: application/vnd.ms-excel');
header('Content-Disposition: attachment;filename="hogaboga.xlsx"');
header('Cache-Control: max-age=0');
$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'Excel2007');
$objWriter->save('php://output');
}