Importing Alembic

Hey guys,

I have made two basic animations via a very similar process in blender and exported it via an alembic file, one imports fine into UE4 and the other one doesn’t (with the same import settings), the error on the broken animation I get is : Unable to compress animation data, no meshes found with Vertex Animation and baked Matrix Animation is turned off.

Both animations open fine in blender, 3ds max and houdini; UE4 is the only program that’s having difficulty importing it and I don’t understand why.
Could someone please debug this for me ?

broken animation here:
working animation here: