Do you have an /etc/lsv-wa.config file as shown in the installation
instructions for the web archive interface?

 4. Create a world-readable file called /etc/lsv-wa.config with the following
 two statements:

  PATH xxx
  URL yyy

 where 'xxx' is the absolute path to the directory you've just created in #3

<that is, usually, the /usr/local/etc/httpd/htdocs/archives directory,
but in any case, the directory where LISTSERV is going to create the
listname.html files>

 and 'yyy' is the URL to this directory (preferably relative).  For instance:

  PATH /usr/local/etc/httpd/htdocs/archives
  URL /archives

 This file is required in order for the 'wa' script to be able to find these
 two resources.

Note that until yesterday the unix installation guide did not contain these
instructions but indicated that you "might" need this file.  The instructions
in the site manager's manual chapter 5 have always indicated that the file was
required.  We regret the oversight in the install guide.

Nathan