Symfony 3.1.5 Warning: SessionHandler::read(): Session data file is not created by your uid

Question

I\'m running Symfony 3.1.5 on a Ubuntu 14.04, PHP 7.1 and Apache 2.4.23 stack managed by Vagrant 1.8.6/VirtualBox 5.1.6. I\'m trying to use a simple controller I\'ve made to

Answer 1

If Magento 2 generates this warning,

Just delete already existed session inside var/session folder and its fixed.