I am still having problems with this. I installed the new design extender and the problem is slightly different.
At first I got the same error with the connection file on line 3. So I deleted the connections folder from the live site. Then I typed in the domain and get this error:
Warning: require_once(../Connections/PowerCMSConnection.php) [function.require-once]: failed to open stream: No such file or directory in /home/daryecko/public_html/install_cms/logininfo.php on line 16
Fatal error: require_once() [function.require]: Failed opening required '../Connections/PowerCMSConnection.php' (include_path='.:/usr/lib/php:/usr/local/lib/php') in /home/daryecko/public_html/install_cms/logininfo.php on line 16
It seems to not be creating the connections folder anymore. I really need this looked into.
Also, after creating the new site with the "new extension" my index.php page only has this in the code - <?php header('Location: admin_cms/users_login.php'); ?>