I experience the same problem. Since the packed mailman-bundler 3.0.0 still has a problem (fix already commited, not yet released) I checked out the current release using bzr. Testsetup was done using mailman-bundler, installation and startup done according to README.rst. Creating a domain worked fine for me. But after creating of a list the error occured. Going back, the list seems to have been created. But trying to open the list-details I get the same error. So I think it might not be the list-creation but the display of list-settings afterwards. Traceback: http://dpaste.com/221P4HS -- You received this bug notification because you are a member of Mailman Coders, which is subscribed to Postorius. https://bugs.launchpad.net/bugs/1429086 Title: Key error in mailman settings page To manage notifications about this bug go to: https://bugs.launchpad.net/postorius/+bug/1429086/+subscriptions