问题 来自Parse的图像未在iOS 9上加载

我有一个 PFQueryCollectionViewController 由图像填充，在iOS 8.x.x及更低版本上一切正常，但是当我使用Xcode 7 Beta在iOS 9上运行应用程序时，所有图像都是空白的。

这是我用来从Parse中加载图像的代码 PFQueryCollectionViewController

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath object:(PFObject *)object {

    UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"Cell" forIndexPath:indexPath];

    UIImageView *imageView = (UIImageView*)[cell viewWithTag:1];

    if([object objectForKey:@"image"] != NULL) {

        [[object objectForKey:@"image"] getDataInBackgroundWithBlock:^(NSData *imageData, NSError *error) {                

            UIImage *thumbnailImage = [UIImage imageWithData:imageData];
            UIImageView *thumbnailImageView = [[UIImageView alloc] initWithImage:thumbnailImage];

            imageView.image = thumbnailImageView.image;

        }];

        }

     return cell;

}

和

- (PFQuery *)queryForCollection {

    PFQuery *query = [PFQuery queryWithClassName:@"Class"];   

    ...

    return query;
}