2014-07-24 11:50:15.925  *** Assertion failure in -[UICollectionViewData layoutAttributesForSupplementaryElementOfKind:atIndexPath:], /SourceCache/UIKit/UIKit-2935.137/UICollectionViewData.m:787

2014-07-24 11:50:15.927  *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'no UICollectionViewLayoutAttributes instance for -layoutAttributesForSupplementaryElementOfKind: UICollectionElementKindSectionFooter at path <NSIndexPath: 0xc000000000000016> {length = 2, path = 0 - 0}'