Besides making sure your server is running PHP 5.4 or higher, after updating from Symfony 2.3 to 2.6.3, I had to roll back a few dependency packages I found were conflicting and weren’t tested and cleared to work with the newest version of Symfony.  Some of the latest compatibility requirements are found here.  The latest compatibility issues can be found here.

However, the only thing I found to break was something silly and small that never should have been part of my older Symfony project and that had to do with my routes’ controllers.  On occasion, I included “Action” after the method name in the controller declaration and Symfony was okay with it and it’d find the method it knew I meant to use.

However, upon upgrading to Symfony 2.6, the controller methods declared in routes looked for an “ActionAction”, meaning Symfony added the word “Action” at the end of the controller name.  No where in the docs did it ever say to add “Action” anyway, it was an oversight on my part that this newest version of Symfony does not allow.  So, check your routes to make sure you leave out “Action” at the end of the method name for the controller method the route is supposed to send the session to or you’ll get an error.

– Aaron Belchamber