There was a compilation error while loading the UBB.classic libraries and data files:
Can't locate /var/www/cgi-bin/ubb/vars_display.cgi in @INC (@INC contains: ./Modules . /usr/local/lib64/perl5 /usr/local/share/perl5 /usr/lib64/perl5/vendor_perl /usr/share/perl5/vendor_perl /usr/lib64/perl5 /usr/share/perl5) at ultimatebb.cgi line 129.