iOS：“ [Fabric]”似乎“ Crashlytics”不是有效的面料套件

我已经更新了 Crashlytics ，但在启动时仍然出现此错误：

I have updated the Crashlytics but still I am getting this error on launch:

错误：***由于未捕获的异常'FABException'，
终止了应用程序：'[Fabric]似乎 Crashlytics不是有效的Fabric
套件。请确保仅将面料套件传递给[Fabric with：]。'

Error: *** Terminating app due to uncaught exception 'FABException', reason: '[Fabric] It appears that "Crashlytics" is not a valid Fabric Kit. Please make sure you only pass Fabric Kits to [Fabric with:].'

这是我的代码 ：

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
        // Override point for customization after application launch.
         Fabric.with([Crashlytics.self])
         return true
   }