No Calendar display in webclient

[Johannes Graumann]

Hi all (Hello Gunnar ;0),

I am running 2.2.2 happily. The only trouble I have is with the webclient. 
Currently I have access to all aspects of kolab from the horde interface, 
BUT the calendar. Address books (turba), notes (mnemo) and even tasks (nag) 
are accessible, but choosing the calendar (kronolith) just leads me to an 
empty page. Where to look to debug this?

Thanks for any help,

Sincerely, Joh