I finally completed all of the December Extra Credit "lessons." It took me well over an hour, whereas it usually takes me less than a half-hour. At first I couldn't get any of the 3 separate lessons to load, except for a shaded area for each lesson with a brown-colored progress bar (it's still that way, as I write this). Then I discovered that by clicking within the shaded area, a dialogue box appeared which reads "Change Lesson." Clicking on that brought up a drop-down menu with the names of the 3 lessons you can choose to view individually and work on.
Even after all that, I had to re-take about a quarter of the quizzes or videos because I didn't receive any points for taking them the first time. Maddening!
All of the points-only gift cards are for a measly $5 so you aren't missing much of any value if you don't complete the Extra Credit promptly. The only one of those $5 cards I really wanted was the Home Depot card, and that was already sold out 45 minutes after the deals opened. Grrrrr...
Good luck to all out there.