It seems to be as if there is a problem with a key in the registry. Therefore please open the registry via inserting the word “regedit” in the start menu and click on enter. Then please be so kind to delete the whole DIALux 2.0 entry in the registry. You will find the folder under: HKEY_CURRENT_USER\Software\DIAL GmbH\DIALux 2.0
After a restart of DIALux the problem should be solved.