The puzzle did not have blanks corresponding with the numbers. The numbers themselves were shown, as was the \, but it had a blank associated with it, even though it was shown.
Pre-crash, I hit a couple of puzzles with "special characters" associated with puzzle blanks, and as with the one noted above, they required a letter filled in - any letter. In one instance I used a letter that had already been used in the puzzle, and it took it anyhow.
I don't object to numbers in the puzzle - sometimes those can provide good clues as to the words around them.