Hi. I’m getting this error both in web and Android versions of the “Learn new words” exercise for “Norwegian 2” course, level 12 (Buying Supplies).
I have 19/20 words learned and it looks like this is the cause of the issue. Some threads on the forum describing this error says that error comes from the +1 bug.
Anamnesis: I have the latest Android app, I reinstalled it, cleared app data and redownloaded the course. Then I opened it in the browser and got the same error, though with the different wording.
Two other users reported the same problem. They were learning: Norwegian 2 for British English speakers, but I believe it is the same kind of problem (see here and here).
A level is written that there are, for example, 20 words, but in reality there are only 19. With this, when you finish the course, learning all the words, the program will think that there is still a word to learn.
You’re right to post your problem here. But, if you have not done so yet, you can submit a bug report: