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.<

Answer 1

I just had a similar issue with Symfony 3.2

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

After hours, we finally found the issue was related to session.cookie_secure (https):

Our production environment uses https, thus forces cookies to be secured over https. The dev environment used http. After moving the dev from HTTP to HTTPS, problem was fixed.