well actualy nothing, but what I know is in rc1.5 installation when you install joomla there is not a sample data installed by default so you need to click on the button when you install, there is a button for installing sample data. so 1 time when I installed I also got empty page only a part of header was showing and notihng alse. after wehen I reinstalled the joomla with sample data and installed the template it was ok, only for the janews module I needed to enable legacy in plugins, other wise I was getting whole site of error, after that now my site is working except the header images are not showing. and janews module is showing only the first news, when it goes to next it show errors again.