I am trying to obtain an instance of my live wallpaper engine in another class, here is my code... In the other class: WallpaperEngine wpe = (WallpaperEngine) LiveWallpaperService.onCreateEngine(); In LiveWallpaperService: @Override public Engine onCreateEngine() { // TODO Auto-generated method stub return new WallpaperEngine(); } But when I refer to an object in my engine (i.e, "wpe.variable"), I get a NullPointerException and the wallpaper force closes.