Why does my puzzle have no solutions?
Not every combination of entries leads to a valid Sudoku. A proper Sudoku always has exactly one solution. If you see "No solutions", it usually means there is an error in the entered numbers — for example a mistyped entry or a misread from scanning.
In this example, the only number that fits in the circled cell is 9, but there is already a 9 in that column. The solver cannot find a valid solution.