warforged cannot be raised as undead

For a warforged, the relationship between body and soul is such that they cannot be raised as undead. 
To clarify:

1. Spells that manipulate a warforged body as a vessel to create an undead servant (Animate Dead (DnD Beyond), Create Undead (DnD Beyond) and the like) fail. 
2. Necromancy spells that deal damage, heal, resurrect or raise as a living creature function on warforged normally.

It may be possible to treat a warforged body as an object for other purposes, but the specifics of bonding the soul to the material body is different enough for a warforged that it can only be done as a living creature (insofar as "living" is a term that applies to warforged).

Type

Metaphysical, Supernatural