ValueError: Unable to configure handler 'file': [Errno 13] Permission denied: '/var/log/mailman-web/mailman-web.log' After I corrected permissions for log file mentioned I can access Postorius and Hyperkitty. Everything looks working, I will test in more details later.

Ah, right, the fact that you have to create the directory and set the permissions for the production setup was not added in the README file. I'll fix that. I'm however surprised that you didn't get the error in your Apache logs without uncommenting the ErrorLog directive. Do you have anything in your apache error log?

Aurélien