This may be due to old version of Comfigurator or Comfort or UCM firmware.
Which version of Comfigurator are you using? Upgrade to 3.4.0 at least if you are using an older version, go to http://www.cytech.biz/comfigurator.html
Also which firmware version of UCM/KNX and Comfort do you have?
If you are not sure, open your cclx file, go to Modules, and Scan all modules which will discover the versions of all modules then save the result and send to firstname.lastname@example.org