Does anyone know how to lower stairs?

I'm using Ultimate Doom Builder right now and I can't seem to get some stairs to lower consecutively, it just seems to lower once and halt without further movement. Any idea how to get it to work properly?

(PS, I keep getting an error when I load up GZDoom to test it which says '(null): Invalid ACS Module'

It's a bit confusing to use, and the docs don't really say how it works, unfortunately (I just saw that there's actually a page on the Wiki about stairs: https://www.zdoom.org/wiki/Building_stairs).

What you have to do is to only give the first sector a tag, and the rest of the sectors have to alternatingly get the "Stairs Special 1" and "Stiars Special 2" specials. Like this:

Example WAD is attached.

stairs_builddown.zip

Aaaaaaah... I can see why it's confusing. Works perfectly, thanks a bunch! I'll try and remember that for future reference :)

It worked! Thanks Boris! Glad to have this solved.

I made a demo map a while ago, demonstrating most types of stairs as well as some advanced effects.