Update Error in Payment & Shipping Setup

Last Wed when I was updating data in the Authorize.net payment module, all was working fine. Today when I try to update information in my Authorize.net module, I am suddenly getting the following error:

Warning: Variable passed to each() is not an array or object in /home/domain/www/www/admin/modules.php on line 56

Warning: Cannot modify header information - headers already sent by (output started at /home/safecutters/www/www/admin/modules.php:56) in /home/domain/www/www/admin/includes/functions/general.php on line 34

I also installed the Edit Order module, but again, there were no modifications to the admin/modules.php file.

Any help will be greatly appreciated!

After a lot of trial & error I found a fix.

In the admin/includes/configure.php file I forced the admin area to the secure server:

define('HTTP_SERVER', 'https://www.domain.com');

Updating now works with no errors.