Constant MOVE_CHILDREN_RETIRED 

pub const MOVE_CHILDREN_RETIRED: &str = "`moveChildren` is gone: a caller's children are drawn where the caller is, as a range of the retained tree's tape (`vdRangeOpen`/`vdRangeClose`), and placed where the callee says `{children}` (`vdSlot`) — which an LGX component's view does for you.";

What a call to moveChildren is refused with, on every tier.