Recheck the Owner's Manual appendix on permissions and be sure you have all of the directories set properly. The manual is available buy clicking
hereIf you are not sure all files have been uploaded, reload the entire set from the zip file
except those that start with vars_ (they are your configuration settings).
Do upload those that start with vars_wordlets All of the vars_wordlets go into the cgi directory. Verify that the Modules directory and all contents are in the cgi directory and that the Templates directory and all contents are in the nonCGI directory.
Post the exact URL to your ultimatebb.cgi if it is accessible from the web. Upload the ubb6_test.cgi file your cgi directory and run it from your browser to help check permissions and the locations of critical files.