I was having the same problem and after several days of frustrating wrong responses from tech support, I finally browsed through many of the messages on this support board and was able to discover that you need to make a change in the 'calendar_admin.pl" file in line 322:
$admin_template_dir = $AdminConfig->get("admin_template_dir") | | "English";
As best as I can figure it out, there was a change in the way that the GoDaddy servers are configured, but someone forgot to change the reference on the server. They used to use sbox but no longer do, so the script is asking the server for the CGI URL and is being returned a directory structure which includes "http://www.yourdomain.com/cgi-bin/sbox/script.CGI" and it is no longer correct. We now need to list our CGI URL as "http://www.yourdomain.com/cgi/script.CGI". By replacing the above line in the calendar_admin.pl file, though, you go around this by having the script obtain the CGI URL from your config.txt file instead.