creator Sorry for my reply is so late, because I didn't check this website few days. It's okay that it haven't a solution for that and of course if you found it, that would be very impressive.
And there is another bug(?) appeared. When I delete the Oxford English-English dictionary, a lot of saved word just gone. So before I delete it, it should have 2000+ saved word, but now only have 3 of them.
Another question, if I uninstall lookupper and install it again, would my pro state disappear? The reason I ask this is lookupper seems like didn't need to sign up or sort of thing, so I was wondering whether pro state will gone when I uninstall it. Also I need to change a drive or folder of lookupper so that I want make sure it won't happen.