In the admin configure.php there is this:
PHP Code:
define('DIR_FS_ADMIN'preg_replace('#/includes/$#''/'realpath(dirname(__FILE__) . '/../') . '/')); 
I assume the preg_replace was introduced in 1.53 to ensure that a /local version of this file produced the correct path as otherwise it has /includes on the end...or \includes for a windows server, in which case this regex does not work and the define is incorrect.

I have changed it to this:
PHP Code:
define('DIR_FS_ADMIN'preg_replace('#.includes$#'''realpath(dirname(__FILE__) . '/../')) . '/'); 
which seems to work ok in windows and linux in /includes/local and /includes.