Symfony 3.0.1 CSRF token present but invalid

Question

I am having this strange issue with a fresh Symfony 3.0.1 installation. I generated a new CRUD Controller with a Form PostType which contains an url and a title. Nothing fancy.

The form is rendered as expected. It contains both my url field and title field. Inside the form the hidden input field _token is also rendered.

When submitting this form, i am getting all the time the following error:

The CSRF token is invalid. Please try to resubmit the form.

So the token is added to the form, it contains a value, i have a constant PHP session cookie value, it is just that this token invalid.

I have searched for other answers but the similar questions are all caused by the absence of a _token input.

This problem also occurs in Symfony 3.0.2/3.0.3.

Answer 1

In my case it was that the var/sessions/ folder wasn't writable. The default is var/sessions which is set at config.yml.

session:
    # http://symfony.com/doc/current/reference/configuration/framework.html#handler-id
    handler_id:  session.handler.native_file
    save_path:   "%kernel.root_dir%/../var/sessions/%kernel.environment%"

Make sure you have var/ folders writable.

chmod 775 -R var/sessions/
chmod 775 -R var/log/
chmod 775 -R var/cache/