I have Craft running locally, the latest 2.x branch. When I change the server to run PHP 7 instead of 5.x, the local Craft frontend still works, but I can't login to the backend. It says "Invalid username or password", even after doing the reset password process.
Trying to prep a site for upgrading to Craft 3, but if I can't even get Craft 2.x running on PHP 7... :-/