Damn, my apologies for the mistake, but there is a problem with the traditional and sdk packages for alpha-4. You can fix it by going to the following files and editing the define for MODX_CORE_PATH in each (this is done automatically in the advanced package).
In manager/config.core.php:
define('MODX_CORE_PATH', dirname(dirname(__FILE__)) . '/');
to
define('MODX_CORE_PATH', dirname(dirname(__FILE__)) . '/core/');
In connectors/config.core.php:
define('MODX_CORE_PATH', dirname(dirname(__FILE__)) . '/');
to
define('MODX_CORE_PATH', dirname(dirname(__FILE__)) . '/core/');
In config.core.php:
define('MODX_CORE_PATH', dirname(__FILE__) . '/');
to
define('MODX_CORE_PATH', dirname(__FILE__) . '/core/');
The advanced package does not have this bug. I will get this corrected and upload alpha-5 this afternoon.