There are 3 steps you need to take to ensure SEF URLs, using the default Joomla! tools, works in a way that will be compatible with Cartage.

1. In Global Configuration, in the Site Tab, set all 3 SEO settings to on.
2. Rename the htaccess.txt folder in your Joomla! root directory to .htaccess
3. Ensure that no value is set in the live_site value in the Joomla! configuration file. This can only be done manually, as there is no setting in the Global Configuration to do this automatically.

Other methods will be valid, and other SEF URL creator components may work. We cannot guarantee they will, nor can we provide instructions on getting them to work with your installation sorry.