The Old Column is a tricky barrier. It can be broken only when chips fall down on it from at least three cells height directly from the column above, not from neighboring columns. In most cases a match of three vertical chips works to break the Old Column, but not always. Here are samples of situations where slab will not be broken:

1 - If there is an obstacle above the Old Column, it can prevent chips from falling on it from the required height. The chips fall not directly from the column above but diagonally from neighboring columns in such cases. The Old Column can't be broken in this case. You need to remove that obstacle first.

2 - If there is an empty cell above the Old Column, it prevents chips from falling on it from the required height too. An empty cell is considered as an obstacle for the Old Column in this case. You need to fill the empty cell with a chip first. See if there are other obstacles that do not let the chips fill the empty cell. You need to remove them.

3 - A match of four or more vertical chips on the edge of the board can make chips fall diagonally from neighboring columns. As a result, the Old Column can't be broken. To ensure the chips drop straight from the column above, make a match of only three vertical chips.

If you still experience any difficulties, please feel free to contact our support team.