this puzzle gives an error message with version 1.5.1.4
*-----------*
|8..|1.4|..9|
|.5.|9.2|.3.|
|..4|...|7..|
|---+---+---|
|..9|6.8|2..|
|7..|...|..3|
|..8|7.3|1..|
|---+---+---|
|..5|...|6..|
|.8.|5.6|.4.|
|6..|4.7|..2|
*-----------*
while version 1.5.1.2 accepts input (I didn't check version 1.1.5.3).
BTW this is a very hard sudoku from Sudoku-Puzzles.net.
Same problem with other puzzles