What a response! Thanks to you all. the missing line was r3
X X 8 | X 3 X | X X X
X 6 X | 9 X X | X 4 X
5 X X | 7 X X | X X X
7 5 2 | 3 8 9 | 4 6 1
3 8 X | X X X | X X 5
X 1 9 | X 2 X | 8 7 3
X X X | X X 3 | X X 4
X 2 X | X X 1 | X 8 X
X X X | X 4 X | 1 X X
I look forward to your comments