An error in Puzzle 6 caused problems for a few solvers. I understand and agree with suggestions that I should have test solvers. However, the idea of having someone to not be eligible for prizes irks me.
So what I do the last couple of years is this: I launch an event. And then I stay in front of the computer screen for a few hours until several entries start trickling in. The early solvers essentially act as test solvers and, even better, they can still win prizes. What happened last night was that Nikoli Hurdles 3 started and a moment later, I received a handful of submissions.
Thinking nothing went wrong, I went to bed and then to class. Now I realize (from a lot of emails) that Puzzle 6 indeed had multiple solutions, it is fixed now. I hope this does not distract you too much and I will try even more to get rid of these errors in the future.