The only thing that I can see that could be wrong is that you push the upwards arrow to the bottom and use a downwards arrow to allow movement below the box, but the other downwards arrow can't be gotten without the box (which means that the plan with the upwards arrow would not work), and the other downwards arrow in the previous level cannot go farther than the ladder. That would mean that the issue once again comes up that you can't get the arrow to move to the left without moving it so that it is next to the box, which means that it would push the box off the ledge before being in position, or pushing the upwards arrow off the ledge, which means that you would get stuck pushing it to the right. So once again, it does not work.