I stop my 2 years diamond. The answer "the site no longer wanted to maintain" does not sound professional.
The Old Lessons are gone and so is my 10 year Diamond membership

Those old lessons and associated rating system was the backbone of my chess carrier. Just because of that I won many prizes in chess tournaments.
Hints were also designed in such a smart way that it wouldn't reveal the whole solution at once. Even after getting hint, I had to struggle& work hard to solve the puzzle. This 'struggle' turned me into a very lethal player, even though my rating was low.
New lessons have following cons:
1- They have broken it in to too short small small puzzles. It has become very easy to solve.
2- no 'punishment' for wrong answers. Old lessons' fasinating rating system would loose you rating points for wrong answers, which made me very focused and precised while solving.
3- using hint option more than once would also cost rating points, so it gradually turned me into a self-dependent solver with positional, tactical & strategical skills, which is a real life situation over the board. ( I mean, during the tournaments there is no one to give you a hint. you have to win it on your own).
So yes, please restore the old lessons.
Eric has brought back over 300 of the old text lessons and placed them in the Masters section. Thanks Eric!