Upgrade 2.0.2 to 3.1.10 session problem on local mamp

The session cannot be said to be working when you set session data and then, after a redirect, cannot find that saved data in $_SESSION.

Your problem might be the configuration or it might be the Authentication library implementation. What you describe has been traced to configuration problems time and time again.

Maybe if you examine cookie creation and which cookies are being transferred to/from the browser/server it will help you confirm that the cookie config is good. It may not be the problem. In which case it is probably custom code implementation.