Problems with knxd installed by openhabian1.4

Hi there

I have installed openhabian1.4 on a raspberry pi 3. My linux skills are limited but it was a smooth setup, Server started up fine. I was able to get my Zwave devices running and my Zmote.

I used the openhabian-config option to install knxd to connect to my Gira USB Gateway.
Installation goes through without errors displayed.
I edited /etc/default/knxd and choose the last line for USB interface.
But I don’t get it to work. That is where I got stuck and with several evenings consulting Google don’t get anywhere.

When installation is done it suggests to type knxd – help. But that returns
Usage: knxd configfile [main_section]
Please consult /usr/share/doc/knxd/inifile.rst

There is no such directory (I get up to doc and then there is no knxd directory)

Same for knxd – version

I tried to use knxtool but with or without sudo and for all options I tried (like knxtool log ip:localhost) I get the message:
Open failed: Connection refused

Does someone have an idea what I’m doing wrong?

If this is not enough information I’m happy to provide more if you can tell me what you need to know about the setup.

Best Regards