I think the problem is that my wiki is private and therefore needs to be logged in to use API. Perhaps generate_family_file.py is not prepared for handling private wikis.
I tried to create the family file manually, but I get the arror when running: You need read permission to use this module I got to the page http://www.mediawiki.org/wiki/API:Quick_start_guide#Logging_in Now I need help in completing user-config.py to log in. My user name is filled in, but the bot does not ask me for the password!