linemode brower error (running on win16)

I have managed to get the wwwlib and linemode browers compiled and running
on a 16 bit windows machine. I can connect to www servers and view the source 
but if I try to view the document as a html file I get the following
error message:
WWW Alert: Fatal error 501 Not Implemented Can't convert from www/mine to 

Does anyone know exactly what this error means. I'm sort of new to http an the 
cern library so if this is a dumb question please excuse.

Chris McNeil