Hi, regarding the library import, can you please post the exact error? What do you mean by "installing" the local package? You should import it into your project by using Tools > Import Local Package instead.
Regarding the demo project, I actually saved it in 2023.8 by mistake, so that's why you couldn't open it (you seem to be using a 2022 Gamemaker version). I uploaded the LTS version of the YYZ demo project. Hope it helps!