Error including libraries: Can't locate /opt/http/firecenter/cgi-bin/links/admin/links.def at /apps/apache/htdocs/firecenter/cgi-bin/links/admin/links.cfg line 124.
Compilation failed in require at /apps/apache/htdocs/firecenter/cgi-bin/links/modify.pl line 44.

Make sure they exist, permissions are set properly, and paths are set correctly.