Hi Josh,
in the end the problem was pretty simple.
The template (Lensa) was the reason – which was pretty old as well. Now everything is up and running 🙂
both did not help! Any further ideas? At the moment the Event does show up when called via the URL http://berliner-teufelsberg.com/web/?tribe_events=silvester2014
However, there are several problems:
1) No valid link from the event overview.
2) Begin/End of the event are broken (see URL above)
3) Checkout does work but brings up an 404 as well.