Well done for giving the kata a fair crack. I've just come across it and felt the current description is really easy to understand—will have a go shortly as this looks like a fun one!

Can you consider to change your feedback? If you think that now it's worth to complete the kata :)
Edit : Thanks!

Thank you very much for all the suggestions! I updated the description , Do you think it's ok now?
I thought the description was clear because I 'invented' the problem and it made sense to me in the way it was implicitly , but (now) I see that it's much better with what you suggested.

Added the following which should clarify:

Note that a "row" in this context is defined as a horizontal row, and the column value of a cell is its
position in its respective row starting from the left-most cell.

I thought it was obvious from the example given. If you look at the positions of the numbers in the initial state, there's only one possibility. Also the example_solution below (taken from the Description) illustrates the rows and columns as well.

example_solution = [
    [    6,9,8,4    ],
    [   2,3,7,6,5   ],
    [  8,6,0,3,1,9  ],
    [ 7,4,1,5,6,2,3 ],
    [  8,5,9,2,4,7  ],
    [   9,2,4,1,5   ],
    [    1,7,3,8    ]
]

In any case, I'll go ahead and add to the Description to make it crystal clear. Thanks for the heads up.

fixed.
thanks!

Not anymore ;)

Thanks.
Fixed.

When you redact a document, all you are doing is using a black pen to hide words.
You are not (can't!) change the "structure" or "format" of the printed page, using a black pen.
And \n is a structural element.

Because the return value is language dependant, what would be more appropriate would be to add something to the description. It does say --- see samples, but this would be more explicit:

If a string contains all repeating characters, it should return an empty string ("") or None -- see sample tests.

could become

If a string contains all repeating characters, it should return an empty string ("") or None, depending on the language (see sample tests for more details).