3D Object with Sprite Img on Face will not display

I'm trying to use the image from a 2D sprite as the facing of a side on a 3D object.

However, when I apply this using the appropriate action line, that side is suddenly blank, as if it was unchecked to be invisible. But it's the only one checked to be visible. I also tried to use both an action line in the Event Sheet and also in the 3D object Properties Bar to assign a simple sprite image to the one face of the 3D object. It still will not show up, making that face appear invisible in the process.

WHAT is causing this?

I have the 3D camera set to parallel with the layout and other than that, nothing out of the ordinary is going on. It's still that ONE side that has the 2D sprite pasted onto it that's blank when it should be visible.

I have triple-checked that the correct side is referenced.

EDIT: I discovered that I needed to have at least a single instance in the layout (or any layout?) in order for the sprite image to appear on one of the faces of the 3D object. I solved my own problem. I'm leaving the post up for others in case they face the same issue.

...now, I have to figure out how to get the transparent space in the original sprite image to appear transparent on the 3D object facing...

The 2D object you're using, it's separate from the 3D object, yes? Like an animation?

Test it this way:

1. Make sure the 2D object is on the layout (I know, I know, just do it)

2. Make sure you have the correct 'face visibility' box checked and you have something in 'use object image for faces' and it's the right something.

But again, if you're doing all this in an 'Object Repository' layout, make sure you also have the 2D image on the layout that you are using the 2D object in (aka the game layout) or it doesn't show up.