Quick answer: Unreal Niagara skeletal mesh DI returning no data when mesh is instanced via ISM? ISM doesn't expose skeletal data; sample base mesh instead.
Forest with instanced trees; VFX should emit from leaves; sampling returns empty.
Sample the base mesh
ISM is per-instance transform of a base mesh. Sample base; transform by instance.
Or use non-instanced for VFX-relevant
Hero trees as regular skeletal; ambient trees as ISM. Mixed.
Audit ISM use
If skeletal data needed, ISM is wrong. Architecture choice.
“ISM is for mass transforms. Skeletal data is per-instance compute.”
If your project mixes ISM and skeletal VFX, the architecture is upfront design.