Question and Remainder is blocked

Question

So for some reason, i just started, still in basic concepts, and the lesson 5/6 is blocked, not allowing me to go any further. I've completed 1/6 to 4/6 perfectly, but I can't press on 5/6. Is this a bug? Or am i missing something? Do i have to pay or something? There's no indications as to what to do.

Answer 1

Seems course changed much. 2.0 is 4.2 answer. Next lesson is quotient and reminder. It working for me..

Anyways, Either it shows wrong answer, try again or goes to next lesson. Otherwise it may bug.
Close app and reopen, then see.
If not work, Clear cache then see again.
Try update app. If any not work then mail to : [e-mail]
they will resolve bug soon..
Hope it helps...

Answer 2

What is 4/6 answer? Swipe to left is not working?
Is 5 lesson blocked or 6 quiz?

Answer 3

4/6 answer is 2.0 it then says correct, continue, then i'm supposed to open lesson 5/6 displayed in blue but ut won't. I've tried quite a few times redoing 4/6...