Debug mode

This is the first step you must take when your instance is returning errors (400, 500) or something just simply does not respond the way you expect
If you are having issues with your installation, the first step will be to enable debug mode and check for error messages on:
  • Your server's php error log
  • The browser console
  • The browser's network Tab if an ajax request failed
To enable debug mode, edit your configuration file and find this line
define('DEBUG', false);
Change the value to true like this
define('DEBUG', true);
This will try to enable php's logging and error output features.
If you don't know where the php error log file, you will need to ask your hosting provider for help locating it. In some cases they cannot be enabled on the fly. Just as before, your hosting's support team might be able to enable it for you.