It seems as though the main Skeleton and Skeleton Lit shaders for the Unity runtime aren't working for Xbox One.
All our spine characters and assets are rendering out magenta-error colored when we deploy a build with those shaders applied.
However, the Bones shader does work. We can also use various normal Unity shaders and they work - although obviously none of these have the right look we need (Skeleton Lit).
Just seeing if anyone else has had to deal with this already, or has some tips before I get stuck in to the shaders myself.