There are about 102 questions about the armature not deforming the mesh, and I have tried every single one of them. And It's still. Not. Working.
I have utterly no clues as to why the armature isn't deforming the mesh (I've included the file, so you all can play around with it), and the entire mesh has a series of vertex groups - of which all of the bone names match.
I am honestly so confused. The only bone I can get to deform anything at the shoulder.l and shoulder.r. Absolutely nothing else.
If anyone could help, that'd be greatly appreciated!