why wont my demo load (it says i dont have the script)

Okay lets be more specific... i'm trying to take some tutorials, but those tutorials require that i download the demo such as the island demo or the 2D demo, but after i download it, it doesn't put the script with it

well if you took lets say for example a project and copied whats in its assets folder to your game than it would only give you that, you need to copy what is in the library folder into your library folder in order for it to work.