Also confirm that whatever .htaccess file you previously had in your forum folder (when your forum was working as expected), that you still have it in place.
".htaccess" is not part of UBB.threads. This is your web server's configuration file for use running the its Apache Web Server software. It is used to alter the configuration of the Apache Web Server software to enable/disable additional functionality and features that your Apache Web Server software has to offer.
