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 experienced a similar problem with Symfony 4.2 when switching from dev to test environment.

I had the following setting in my framework.yaml file:

framework:
    session:
        storage_id: session.storage.mock_file

Solution:

Removing the storage_id: session.storage.mock_file-setting solved the problem.

Important: You probably have to clear the cache for this to take effect.

For more information about the storage_id-configuration option also see here.