Try spawning the shell on a higher layer than layer 0, or otherwise messing with its z-order to make sure that it's appearing on top of the other objects that are already there.
Also, if you're going to create an object in code there has to exist a version of it somewhere in your project directly on a layout (so that the create expression knows what the default settings would be for the object). I usually just make another layout thats used only for this to toss once instance of my objects I want to spawn onto, or else do it on a load screen or outside of the viewport of the game screen.