Just played a round of Scenario 2, objective B. Loved it, was tons of fun but I have a question. the ladder in the chapel as mentioned in the errata, doesn't lead anywhere until another ladder is placed via clue card. This doesn't make a lot of sense to me. In my senario I made choice 2b putting the other end of the ladder in the chasm. Now my players tried to go down the ladder on turn 2 but since the chasm had the Magic lock I was able to expain their inability to enter on that, but had I placed it in the basement, I would not of had that out. But even without that explination, i find it strange that you can't go down a ladder because you don't know where it goes. That is sort of the point of exploration I thought (the concept not the game mechanic). So I guess what I am struggling for is a thematic concept that explains this inability to ladder climb. Thanks for your time.

just pretend the ladder is not there until both tokens are on the board...

You could say that as long as the other entrance of the tunnel is not found, the marker in the chapel only represents a hole in the ground without a ladder and there is no way to go down (yet). When the investigators find the other entrance there are two ladders and one can be moved to the hole in the chapel to make the tunnel passable in both directions.

That is a very good idea. thanks. Jumping down a hole into darkness is a whole different story than climbing a ladder down.

When players asked what "that thing" is, I explained that it's a ladder. They can move from one ladder-token to another just as they do from one space to another, costs 1 Move Action, etc.
Before they could go on about "but there is no other ladder", I told them that all they see now is a trapdoor and it's locked.

Of course they quickly realized that they'll find the ladder or that an event will reveal it later.