More puzzle bugs

This bug is bad: It teaches that there`s only one mate on 4 in this King + Rook x King elementary position, saying that Kc3 on first move is wrong, but Kc3 also gives mate in 4, so it`s a solution as well.
http://en.lichess.org/training/25572
There are many other kind of bugs, like puzzles that say immediately that you failed, even before you make a move. In this case, you can open the link and solve it without that message. The instant failure message appears only during the training.
And of course, the most ridiculous type of bug: The answer that is considered the right one is a mate in 6, and I found a mate in 5, with Qxf7 first, instead of RxR first, 100% confirmed: http://en.lichess.org/training/49254

You don't need to complain on the forum about every bad puzzle. There's up and downvote arrows on the puzzles for a reason. They're there so bad puzzles don't appear to other players.

BearJs, can you show us the Qxf7 variation? I can't find it by myself.

So annoying. I did the correct line starting with Qh5+ instead of Rxd8 (M5+) and failed it losing 25 points, and the M5+ is certainly not 2120 difficulty. The line: 1... Qh5+ 2. Kg8 Qh7+ 3. Kf8 Qh8+ 4. Ke7 Qg+ 5. Qf6 #

And for the rk vs k bug, there is a M3+ (your line). For the correct line, it is 1 move LONGER. So, why does the shorter line not even score 'good move but there is better' ? And other ridiculous moves such as Re8, Rd8 .... score that. Should-be-correct line: 1...Kc3 2.Ka1 [Ka3 Ra8#] Kc2 3. Ka2 Ra8# (M3) Current line: 1... Rb3 2 Ka1 Kc3 3. Ka2 Kc2 4.Ka1 Ra3# And the rating? Check it.