I like to download the puzzles and just complete slowly over the month, was doing number 13, and have got an unsolvable solution with 1 and 3s in a box shape unable to be placed.
Have checked all boxes, rows and column, and they all contain 1-9, and all skyscrapers have the correct being able to be seen from the end of each row.
Not sure how people are getting answers if the 1 and 3 in row 1 are interchangeable
I am sure you are missing
I am sure you are missing something - probably forgetting about the No touch rule - but please do not talk about the competition puzzles before the contest is over!