Due to the change in Symfony 4.3.3, you can't compile the container due to invalid Session Handler configuration.

Symfony is loading configuration files in alphabetical order which makes it load framework.yaml after ezplatform.yaml. This results in framework.yaml overriding framework.session.handler_id: ~ setting. Symfony now warns about save_path being not used when Handler is set to null.

Another issue is that even after removing handler_id setting from framework.yaml it still fails because in ezplatform.yaml Session Handler is set form env but this is prohibited.