@chrisse Yes, The credentials are alright, they work on several other devices

I have added a Generic CalDav server in Calendar. It seems it has connected ok, I can see it syncs (message). However, the data does not show in Agenda, neither is it possible to show this calendar when adding a new event or select it in the list of calendars.

I have already uninstalled calendar and installed it again, removed the CalDav account and added another etc. Always the result is the same.

Anybody had any luck adding a CalDav account to Calendar? I use a Nexus 5 and OTA-11