CodeIgniter - Blank page on database autoload

in application/config/database.php check that

$db['default']['dbdriver'] = 'mysql';

is set to

$db['default']['dbdriver'] = 'mysqli';

I had a similar problem with blank pages seemingly associated with loading the database, be it via autoload or calling $this->load->database(); in the model constructor. I ended up having to modify my 'php.ini' file by commenting out extension=php_pdo_mysql.dll and uncommenting extension=php_mysql.dll (i.e. turning PDO back off). I am running Windows 8.1, Apache 2.2, and PHP 5.3.27.

This answer is similar to another, but I couldn't add a comment for clarification since I just signed up. It took me a couple of hours and a lot of Googling to resolve, so hopefully this helps somebody.

Are you sure your db connection credentials are correct? If you switchd servers this seems like it might be the issue.

Additionally, CodeIgniter sets error_reporting(0) for production environments --- hence the blank page. Check your logs dir (is it writeable by the webserver process..?) for any other info.