Only 200 people can take the quiz per month. The counter will be reset on January 25th.
Thank you for your input and clarifying things up, my friend! Now this explains it.
The quiz was blocked twice, as twice we reached its upper limit during the third edition of BitcoinTalk Community Awards! I am glad to see that so many users tried the quiz in this interval and, more important,
they also learned a lot while going through the 21 questions.
Excepting that, icopress and I also offered some merits to those which performed the quiz and, for many of them, those were their first earned merits. Thus, together with the required activity, they were promoted to Jr Members. Congrats to all! Some of them also offered some valuable input regarding the quiz (bugs, glitches, answers which needed to be updated etc.) and, in their case, our generosity was bigger. Together with these users the quiz was updated and it reflected accurate information.
I've seen many similar quizes in the past years but, I have to say, none of them ever got the traction this quiz faced. This is really incredible. Most likely, this also happened as there is no other active quiz, as far as I know. Still, participation rate was (and still is) at a very high rate.