Black halberd

[Usada Pekora]

I am stuck at those 6 ights, stalagmites pass has opened, but i can't get past a mossy wall, that is supposedly a hidden door, it just won't open.

[Mattimeo78]

http://www.harehunter.info/Avernum3/Maps1/id122.html

This is the walkthrough for Remote Cavern. It's for Avernum 3, but little enough has changed that it'll see you through the dungeon with no problem.

[Usada Pekora]

Once again. there is a problem in a game, and it's either a bug or that dungeon is different from how it was in exile 3. When you lit 6 braziers, stalagmites do disappear, but there is no passage past them, it is blocked by a wall.

[Mattimeo78]

As it says in the walkthrough I offered, you don't light all six, just the sixth one.

[Usada Pekora]

Have you tried it yourself? There are 7 lights, that are lit at the beginning, the key to solving it is to have only 6 of them remain lit. Once you do that, stalagmites disappear and you can move to the east, except that you can not, there is another wall behind the stalagmites.

[Mattimeo78]

I clearly have the halberd, as I have the achievement for aquiring it. I did exactly what the walkthrough said to.

[Usada Pekora]

https://imgur.com/a/1aYJ4
how much nature lore you had when you were exploring that dungeon?

[Usada Pekora]

Oh now i remember, there have to be a stone inside a crate that you put on a rune, but i can't open it.

[Gon]

There's a hidden switch on the wall nearby that gets rid of the green wall/hedge. You can see it in the screenshot you posted above.

[mcsproot]

An easy way to get the six lights is to hit ONLY the sixth floor panel. Best way to do this is to go into combat so your party doesn't trigger other panels.

Then as was said, on the north wall there is a button to open the path to the next area.