Some problems with WP 3.9.x and PHP 5.4

I have change this lines:

// Allow alternative splash page
				if ( file_exists( WP_CONTENT_DIR . '/wp-maintenance-mode.php' ) )
					include( WP_CONTENT_DIR . '/wp-maintenance-mode.php' );
				else
					include('site.php');

with this lines:

// Allow alternative splash page
				if ( file_exists( get_template_directory() . '/wp-maintenance-mode.php' ) )
					include( get_template_directory() . '/wp-maintenance-mode.php' );
				else
					include('site.php');

and load the custom page on my current theme, it working very well.

Thanks.