Symfony2 POST data is empty when a form is submitted with specific files

Question

I have a Symfony2 form designed to receive a loaded (xml) file and associate it with an entity. The object that needs to be linked is selected from the Select element, so its identifier is included in the POST data when the form is submitted.

Everything worked successfully, but when I try to load one specific XML file, Symfony claims that the POST data is empty - and therefore an error occurs because it cannot find the entity to bind the load to.

In my controller action that handles form submission, if I do,

var_dump($request->request->all());

which returns "array: empty"

If I open the symfony debug panel, it will say:

Request POST Parameters
No POST parameters 

Firebug, POST, , . , POST?

Symfony 2.3.9, . XML XML, .

Answer 1

, POST (post_max_size).

Answer 2

, PHP.ini .

, 8 ( , ) $request->files, .

Answer 3

:

<form action="{{ path('form_submit') }}" method="post" {{ form_enctype(form) }}>

Twig