Mistakes at (7,25) - Column says I need 8 in a row, but it wants to display an X. And at (26,26) - Row says I need 2, but again it wants to display an X. Unable to complete.
I had no problems either KintWich. Is it p;ossible you've got the numbers at side or top crossed out, and with the "Fill in the solved lines/columns with crosses" option checked? If so, it'll keep trying to place an X every time you remove it.