ช่วยด้วยครับดาวน์โหลดไฟล์มาแล้วไฟล์กับเสียหาย แก้ยังไงดีครับ

include("config.php");
if(isset($_GET['pro_name'])){
    $gard = mysql_query("SELECT * FROM project WHERE pro_name = '".$_GET['pro_name']."'limit 0,1")or die (mysql_error());	
   
   $data = mysql_fetch_array($gard, MYSQLI_ASSOC);
   $file =$data['pro_name'];
   $name = "ieup/project/";
   $kk5 = $name.$file;
   header("Content-Description: File Transfer");
header('Content-Disposition: attachment; filename="'.basename($file).'"');
   header("Content-Type: application/octet-stream");
   header("Content-Type: application/download");
  
   header('Content-Transfer-Encoding: binary');
  header('Connection: Keep-Alive');
  header('Expires: 0');
 header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
 header('Pragma: public');
   header("Content-Length:". filesize($kk5));
   flush();
   $fp = fopen($kk5, "r");
   while(!feof($fp)){
   echo fread($fp, 65536);
   flush();
   }
   fclose($fp);
}