Yep, you're right. Thank you

I didn't solve this kata, but reading the discussion I understand that you should return also null if there is more than one solution (what I think the author meant with the condition is not enough). It's probably what's happening here.

this kata works?
in validations says that:
input = [ [ 10 ,null, 8 ], [ null,11, 6 ], [null, 7 ,null] ]
expected result = null
but my result is = [ [ 10, 1, 8 ], [ 2, 11, 6 ], [ 7, 7, 5 ] ]

in my result all lines sum 19

i cry with laughter, hahahahaha!

I haven't finished the challenge yet but i can say that your alternative solution not consider that you can open the "constants". One example of this is:

realSolution[0][3] = 1
yourSolution[0][3] = 2

depending if hidden number is 1 or 2 you can determinate where is the mine.
You can know that this square can be opened becouse in the two options the square is a number (no can be explode)

(I am sorry if it is not well understood. My english is not good)