Spent this morning updating a client’s site to Opencart 1.5.6.4. All went well until I tried to log in to admin, when the admin login screen just refreshed, no error message, nothing in error log. After some digging, I identified that although the site was ussing SSL, the form was being submitted to a non-SSL URL. So it failed. The solution was to edit the admin config.php file to set the HTTP_SERVER constant to use https.
define('HTTP_SERVER', 'http://yourdomain.com/admin/');
There are lots of mutterings on various boards about this, but didn’t see this as a solution…Hope it helps.
Tags: opencart
thank you! it helped me, I was going crazy….