If you are trying to get the menu dropped from the lock screen it won't work. Otherwise it is indeed a bug. Please do a screenshot of all the lock screen desktop widgets, and send them to me (as a bug report if possible). You might also try to reset widgets, by dropping all the cache and settings that are in ~/.config/SfietKonstantin ~/.local/share/data/SfietKonstantin/ and try again (without uninstalling anything)