title: Apple LLVM 6.0 Error UICollectionView
body: <p>I control drag CollectionView from storyBoard to ViewController.h like this</p>
  
  <pre><code>@property (weak, nonatomic) IBOutlet UICollectionView *collectionView;
  </code></pre>
  
  <p>After Build, Xcode has an Apple LLVM 6.0 Error below.</p>
  
  <p>file '/Applications/Xcode6-Beta5.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS8.0.sdk/System/Library/Frameworks/UIKit.framework/Headers/UICollectionViewLayout.h' has been modified since the precompiled header '/Users/alpha003/Library/Developer/Xcode/DerivedData/ModuleCache/1MBMXMEEES6H1/UIKit-14NGSGHI2IEK1.pcm' was built</p>
  
  <p>It doesn't happened before. What is going on?</p>