PHP无法启动下载文件

Question

我想创建一个列表，供我的客户选择数字下载格式然后下载文件。

This正是我所需要的，但是php脚本没有任何作用。

https://finelinecreative/index.php/php

有什么想法吗？ CMS是Concrete5，根据主机，我具有所有正确的服务器设置。

<?php
if(isset($_POST['files']))
{
$error = ""; //error holder
if(isset($_POST['createzip']))
{
$post = $_POST; 
$file_folder = "files/"; // folder to load files
if(extension_loaded('zip'))
{ 
// Checking ZIP extension is available
if(isset($post['files']) and count($post['files']) > 0)
{ 
// Checking files are selected
$zip = new ZipArchive(); // Load zip library 
$zip_name = time().".zip"; // Zip name
if($zip->open($zip_name, ZIPARCHIVE::CREATE)!==TRUE)
{ 
// Opening zip file to load files
$error .= "* Sorry ZIP creation failed at this time";
}
foreach($post['files'] as $file)
{ 
$zip->addFile($file_folder.$file); // Adding files into zip
}
$zip->close();
if(file_exists($zip_name))
{
// push to download the zip
header('Content-type: application/zip');
header('Content-Disposition: attachment; 
filename="'.$zip_name.'"');
readfile($zip_name);
// remove zip file is exists in temp path
unlink($zip_name);
}

}
else
$error .= "* Please select file to zip ";
}
else
$error .= "* You dont have ZIP extension";
}
}
?>

服务器php版本为5.6 谢谢