Today i started with a fresh install of domoticz and OS. I wish i did this before. it is now working.

Thanks anyhow!

After last message i start focussing on python part.
When i run
pi@Domoticz:/ $ python3 -V
Python 3.5.2


But when I try to install the tradfri
sudo pip3 install pytradfri
Looking in indexes: https://pypi.org/simple, https://www.piwheels.org/simple
Collecting pytradfri
Using cached https://www ...

Hopefully somebody can help me here ;)
For serveral days im struggeling with making tradfri working on my pi with domoticz. I followed the steps on https://github.com/moroen/IKEA-Tradfri-plugin . Nowhere i got an error

pi@Domoticz:~/domoticz/plugins/IKEA-Tradfri $ ./configure.py 192.168.1.108 xxx ...