I'm currently making a race track in blender and i'm following this video: https://www.youtube.com/watch?v=SDLLbKvEeBY. At 7:04 in the video he adds the curve modifier and sets it to the bezier. Whenever I add the curve modifier and set it to the bezier,the "cube" just disappears.
Edit: I changed the axis in the curve modifier and now it looks like this.

