Moral error theory says that ordinary moral assertions are truth-apt while failing because the moral properties or categorical reasons they purport to represent are not instantiated. Moral vagueness seems to press against this view: familiar Sorites cases appear to contain clear positive cases, clear negative cases, and borderline cases. Recent work notes a possible reply. Even if moral predicates have no actual instances, they might remain intensionally vague if they could have borderline instances. This paper asks how far that reply travels once the modal scope of error theory is made explicit. The reply is straightforward only for versions of error theory that leave open a vagueness-relevant modal space containing possible borderline moral predications. A necessary error theory, on which positive moral predications are false throughout the relevant possible worlds, cannot simply invoke the same possible-borderline route. It inherits a borderline burden: it must explain what makes some uniformly false moral predications borderline rather than clearly false, or else shift to another modal base, a hyperintensional semantics, impossible worlds, or a non-modal account of vagueness. This result does not refute necessary error theory. It isolates a missing condition in the debate and separates actual emptiness from modal closure.