Principled Baker - Bake PBR textures with a few clicks

I’m trying to use the addon to hopefully prepare some objects that were textured procedurally in Blender and use them in Unreal Engine.

The objects don’t have proper UV maps, and are using a few different UV maps to place different textures and decals.

I’m trying to use the Smart UV Project option. Here are my settings.

When I hit bake I get this error.

Here’s a closer view of what’s going on in the material of the object.