I've also added on the 2nd line of the addon_csf.cgi the following: use CGI::Carp qw(fatalsToBrowser); Which makes the error to be shown on the Broswer. And this is what I get: Can't locate Cpanel/Rlimit.pm in @INC (@INC contains: /usr/local/cpanel /usr/lib/perl5/5.8.8/i686-linux /usr/lib/perl5/5.8....