Assertion Failure in UICollectionViewData validateLayoutInRect on ios7

Question

Assertion Failure in UICollectionViewData validateLayoutInRect on iOS7.

I am trying to delete all UICollectionView items, one by o

Answer 1

- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
    [collectionView.collectionViewLayout invalidateLayout];
    return 1;
}