Thank you, Piotr. I've already implemented the request options since it's the only way I know that can get the info out.
Back to TREAD_BMATS, from the ref. guide (please see the attachment) there's a part with "... of selected (current) tread ..." that throw me off. It kinda suggests that you can apply the label with specific tread (tab-select). Maybe it's just a typo, a copy and paste mistake in the ref. guide.
Even with the stair selected (not tread), text2, 0, 0, tread_bmats doesn't crashed but gives off 0 (zero) which I don't think it's correct.
It's even more ... I would say "surprised" ... that ArchiCad also crashed when the label is applied to a tread with nothing but the following code in 2D
Thank you for sharing the experience and I am sorry about the experience!
Unfortunately, I'm not an expert in GDL, therefore I cannot tell what is causing the issue. I will have our Technical Support team take a look at this.
You mentioned that ARCHICAD crashes when labeling any tread using this. I'm wondering if you can forward to us one of the Bug ID generated by the Bug Reporter? https://helpcenter.graphisoft.com/knowledgebase/64553/