Sample Solution – Step 4
Now put a 2 in cell A1 and press the button.
The “This is an invalid Sudoku grid” message appears. This means that the choice of a 2 in cell A1 was wrong.
In some cases it may attempt to solve the puzzle, in which case you will need to retrieve to partially solved puzzle from the Rough Work sheet (using the select copy & paste functions used before) and paste it back into the Sudoku Grid. However, in this case, simply click OK and continue to the next step. Click here for next step.