I don't mean to sound like a dumbass, but I probably do already asking a question that may have been solved numerous times. The description of the mod clearly states that it doesn't require any file extracting or anything else to install the mod, just simply clicking "Subscribe" will install the addon and you can go to the Steam Workshop on the main menu screen to find the Hazard Course.

Well the Hazard Course does not show up for me, I'm pretty new to Black Mesa and modding is a pretty frustrating thing that I've noticed, and I don't exactly have an above average attention span to be reading all this and following along. Can someone just help me with why the Hazard Course isn't showing up in the Steam Workshop on the main menu?

I did read somewhere that the mod was not compatible with the Old UI system, and that it works better with the New UI system; I also don't know where that is or where to change it.