I have a big problem with your Publisher. New installed, in the backend no changes. Only saving Content -> issues and the frontend is no longer working. The same happens on your demo site. What to do ???
Menu item was leading to "Informations" not "Publications".
Moreover SH404SEF cached redirection and redirects to wrong page... that's why you can't access it.
I disabled it and page is accessible.
I don't have Access to publications and issues at the frontend.
For example I have the menu item http://agenbach.com/de/neues-aus-aller-welt
This is linked to Publisher "List for all publications". But it does't work at frontend. I am redirected to the Publisher Information page.
At the Moment i can't check if publications and issues are working.