Have you already tried this way? if groupBy == 2 { cards.nsPredicate = nil let sortSetID = NSSortDescriptor(keyPath: \.setID, ascending: true) let sortName = NSSortDescriptor(keyPath: \.name, ascending: true) cards.sortDescriptors = [sortSetID, sortName] // This errors cards.sectionIdentifier = SectionedFetchResults<String, Card> // This errors }

Same for me. Reported to Apple, just in case give any clue...