the main.inc.php file needs to use paths, instead of URLs - for instance, /home/kate/domains/kate.com/public_html/ubbthreads
also, the first path ($thispath) is just the path to the ubb.threads installation itself (like my sample above), it's not the path to the install directory (the wording is a bit confusing). the second path should be to your /includes directory (like: /home/kate/domains/kate.com/public_html/ubbthreads/includes) where your config.inc.php is located.
let me know how that goes! <img src="https://www.ubbcentral.com/boards/images/graemlins/smile.gif" alt="" />