Hi,
sorry for the late answer. You are using a SNAPSHOT version of the binding so I suppose you are not using the release version of openHAB. You could try it either with the Release version of openHAB (and then installing a newer version of the binding) or you install the latest snapshot build (https://openhab.ci.cloudbees.com/job/openHAB-Distribution/). Since the release of openHAB there have been quite a lot changes especially in the Homematic binding.
If you only want to update the add-on you can follow the steps in the FAQ Frequently Asked Questions (FAQs).
You can find further information about log files and the traces in the doc: http://docs.openhab.org/administration/logging.html to create traces for the Homematic you would have to issue the command
log:set TRACE org.openhab.binding.homematic
in the Karaf console.
Martin