Lose Your Marbles! will help you identify the problems in your game.  If you select “Find problem” from the “Board” menu, Lose Your Marbles! will search for any rows, columns, or diagonals with duplicate marbles and highlight the first problem pair it finds.  (If it doesn’t find any problems, it will tell you so.)

When a pair of marbles is highlighted, press any key or click the mouse on the playing board to return to normal play.