scene.whyPartial

Answer why a loaded layer is not whole. Returns the nearest cause from a closed set — loaderRaised, entrypointCompileFailed, entrypointBodyRaised, entrypointRaised, buildRaised, entityFailed, parentMissing, parentRefused, parentAbandoned, componentUnresolved, componentRefused, subscriberRaised, updateRaised — with the engine's own words for it and the full list of failures, each naming the entity, component identity or lifecycle hook it is about. A layer that produced everything its scene declared reports ok = true and no reason.