I'm finishing the lesson but progress is not being shown. Right now I am stuck and can't advance.
After completing the lesson, the program stops responding. It doesn't show how many skill points I got or how many words I learnt. Instead, after few moments, the program goes back to the home menu and all progress in that lesson is lost.
Anyway! As it seems the problem was with my browser. I re-installed it and now it is working fine again. Besides I didn't experience this problem when I logged in from my mobile.
So, thanks anyway! :)