Ok, so there are multiple problems here. (I managed to download/test it).
First, name your sprites. I renamed them, it's a lot more simple to read.
Second, you don't use the pathfinding behavior right. First "Find path", then in another event, you use the trigger "on path found", and then you move along path. I changed it in the code.
Using this correctly, and using image points where I want the character to go exactly (in the **middle** of the top and bottom sides), it works more like you wanted it.
Another problem there were was the top of the ladder not being solid, and we would fall through as the platform behavior was resumed. You may have did it so the pathfinding works, but I put again the solid behavior, witch I deactivated, as well as the collisions, in the editor. I activate them as soon as you click on the first ladder. The pathfinding won't be bothered by the solid, as it has already calculated its obstacle map.
Here is the link.
Feel free to ask if anything isn't clear :)