发布隐藏字段时，PHP $ _POST为空

I have the following form that is dynamically generated:

<form action="index.php?route=module/print_wizard/showPrintSheet&amp;token=4ef5f4af6ba25d6096357fdb4809e819" method="post" enctype="multipart/form-data" id="form">
    <input name="[print][6][1]" type="hidden" value="on">
    <input name="[print][6][3]" type="hidden" value="on">
    <input name="[info]" type="hidden" value="INV-GIS-00002-3">
    <input name="[layout_override][6][1]" type="hidden" value="">
    <input name="[layout_override][6][3]" type="hidden" value="">
    <input name="[bundle_override][6][1]" type="hidden" value="">
    <input name="[bundle_override][6][3]" type="hidden" value="">
    <input name="[run_id]" type="hidden" value="14040455">
    <button type="submit">Export</button>
</form>

My PHP code is:

var_dump($_POST);
echo "<HR>".$this->request->server['REQUEST_METHOD'];

I have done this a million times before and can not for the life of me figure out why my $_post array is empty. I have changed my post to a get and all the fields and values are passing, but I need to use a post. Do I need to have one visible form element? Please help!

You are not using valid names for your form fields:

<input name="[print][6][1]" type="hidden" value="on">

is not valid as it just has an array index but no name.

If you change it to for example:

<input name="print[6][1]" type="hidden" value="on">

it will work without any problems.