Yes, don't post here, it's unrelated, use that kata discussion. And if it is the 2kyu one (there are 2 katas with the same name):

Or it should raise an error in cases of: invalid grid (not 9x9, cell with values not in the range 1~9); multiple solutions for the same puzzle or the puzzle is unsolvable

So I guess you've found one solution but there is more than one.