hope this fix your issue I answered your other post as well, but just to reiterate: You named your controller "verify_login.php" but your class is named "VerifyLogin". In Codeigniter your class needs to be named the same as your file, just with capital letters. In order for that page to work correctly you should either rename your controller file to "verifyLogin.php" or rename your class to "Verify_Login".
OpenAm (as IdP): SSO login returning NoAuthnContext (unable to login with SSO)
this one helps. This flow chart helped me understand what's going on: https://www.varnish-cache.org/trac/wiki/VCLExampleDefault. Essentially, after calling return pass, the request passes through vcl_pass, vcl_fetch and vcl_deliver. In my VCL config, cookies were being stripped out in vcl_fetch and now that it's clear the a pass will flow through there, I see why I cannot login.
How to stop Centos 7 Desktop returning to Login Screen after a successful login?
Any of those help Interrupt the boot at the GRUB stage and boot to runlevel 1, AKA single user mode. Interrupt GRUB by typing a character such as "space" then append to the kernel line by typing "a", backspacing through "rhgb quiet" and appending " 1". This will give you a root shell and not a login prompt. From there you can comment all recent entries in /etc/environment , and reboot your server/PC
Parse and Facebook sdk 4.1 login and signup returning "User Cancelled Login" Objective-C