The sandbox is not in sync with the Podfile.lock. Run 'pod install' or update your CocoaPods install

I. Project Cleanup

1. In the project navigator, select your project
2. Select your target
3. Remove all libPods*.a in  Linked Frameworks and Libraries

II. Update CocoaPods

1. Launch Terminal and go to your project directory.
2. Update CocoaPods using the command  pod install

注意，1.3很重要。