maatwebsite/laravel-excel returns corrupted file while exports in Live Server, but working in Localhost

• PHP version 5.6
• Laravel 5.2
• maatwebsite/excel: 2.1.0

The code below works fine in localhost, but when i check with Live Server (AWS Light Sail), returns Corrupted Excel/PDF File. I have given all required permissions recommended by maatwebiste. And when i try to dd() the result inside the function the server returns 500 Internal server error response. When i check with some forums someone saying the problem occures with while spaces inside the function and before the < ? php Tag, I tried with the solution but returns the same. Any Help Would be well appreciated.

 public function export(Request $request, $type = 'pdf')
    {
        try {
            $data = $this->getReport($request->All(),new ServiceReport());
            return Excel::create('service_report', function ($excel) use ($data) {
                $excel->setTitle('ServiceReport');
                $excel->setDescription('Service Repor');
                $excel->sheet('AxisPro-ServiceReport', function ($sheet) use ($data) {
                    $sheet->setOrientation('portrait');
                    $this->setColumnHeader($sheet,['Invoice No','Date','Customer']);
                    if (!empty($data)) {
                        foreach ($data as $key => $row) {
                            $i = $key + 2;
                            $sheet->cell('A' . $i, $row->invoice_no);
                            $sheet->cell('B' . $i, sql2date($row->transaction_date));
                            $sheet->cell('C' . $i, $row->customer_name)->setAutoSize(false);
                        }
                    }
                    $sheet->setPageMargin(0);
                    $sheet->setBorder('A1:' . $sheet->getHighestColumn() . $sheet->getHighestRow());
                    $sheet->row(1, function ($row) {
                        $row->setBackground('#d9d9d9');
                    });
                });
            })->download($type);
        } catch (\Exception $e) {
            throw new \Exception($e->getMessage());
        }
    }

via Chebli Mohamed