OK, I see, the admin folder was renamed to admin_cms in the latest update. sorry for the confusion.
where the login page is showing blank, it indicates that a php error is occurring but error reporting is turned off.
add the code at line 1 to turn error reporting on:
<?php
error_reporting(E_ALL);
ini_set('display_errors','on');
?>
the cause of the error will likely point us to why the install is not starting.