Why does the formatting disappear after enabling SEF URLs?

From Joomla! Documentation


Redirect page
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.

Depending on the PHP version you are using (for example, version 5.2.6), the configuration.php file might need to be changed as follows:

var $live_site = 'http://www.yoursite.com';