The Ikonboard system used by CPNN prior to 2015 is no longer fully supported and the discussion links are no longer valid. See below for instructions to access them.
http://cpnn-world.org/cgi-bin/ib3/ikonboard.cgi?s=;act=ST;f=32;t=254 [where 254 is the topic number]
and it will tell you that there is an INTERNAL SERVER ERROR:
However, it is still possible to go to the discussion by using the topic number..
Simply plug the topic number into a new URL as in the following example: