title: iOS Undefined symbols for architecture x86_64 Xcode
body: <p>I have installed some third party frameworks in my app. Every thing was working fine and suddenly one day i started to get the following errors. Please note that these linker errors appear only when i try to run my app on iOS Simulator.</p>
  
  <pre><code>Undefined symbols for architecture x86_64:
    "_AFNetworkingOperationFailingURLResponseDataErrorKey", referenced from:
        ___61-[DataManager signupWithEmail:password:name:success:failure:]_block_invoke.127 in DataManager.o
        ___46-[DataManager favoriteLesson:success:failure:]_block_invoke.311 in DataManager.o
        ___48-[DataManager unfavoriteLesson:success:failure:]_block_invoke.345 in DataManager.o
    "_AFStringFromNetworkReachabilityStatus", referenced from:
        ___41-[DataManager startObservingReachability]_block_invoke in DataManager.o
    "_OBJC_CLASS_$_ADJConfig", referenced from:
        objc-class-ref in AppDelegate.o
    "_OBJC_CLASS_$_ADJEvent", referenced from:
        objc-class-ref in TrackingHelper.o
    "_OBJC_CLASS_$_AFCompoundResponseSerializer", referenced from:
        objc-class-ref in DataManager.o
    "_OBJC_CLASS_$_AFHTTPRequestSerializer", referenced from:
        objc-class-ref in DataManager.o
    "_OBJC_CLASS_$_AFHTTPResponseSerializer", referenced from:
        objc-class-ref in DataManager.o
    "_OBJC_CLASS_$_AFHTTPSessionManager", referenced from:
        objc-class-ref in DataManager.o
    "_OBJC_CLASS_$_AFJSONRequestSerializer", referenced from:
        objc-class-ref in DataManager.o
    "_OBJC_CLASS_$_AFJSONResponseSerializer", referenced from:
        objc-class-ref in DataManager.o
    "_OBJC_CLASS_$_AFNetworkReachabilityManager", referenced from:
        objc-class-ref in DataManager.o
    "_OBJC_CLASS_$_AFURLSessionManager", referenced from:
        objc-class-ref in DataManager.o
    "_OBJC_CLASS_$_AMTagView", referenced from:
        objc-class-ref in CategorySelectionViewController.o
    "_OBJC_CLASS_$_Adjust", referenced from:
        objc-class-ref in AppDelegate.o
        objc-class-ref in TrackingHelper.o
    "_OBJC_CLASS_$_CarbonTabSwipeNavigation", referenced from:
        objc-class-ref in MyProfileViewController.o
        objc-class-ref in SearchResultsContainerViewController.o
    "_OBJC_CLASS_$_FBSDKAccessToken", referenced from:
        objc-class-ref in SignUpViewController.o
        objc-class-ref in MyProfileViewController.o
    "_OBJC_CLASS_$_FBSDKAppEvents", referenced from:
        objc-class-ref in AppDelegate.o
    "_OBJC_CLASS_$_FBSDKApplicationDelegate", referenced from:
        objc-class-ref in AppDelegate.o
    "_OBJC_CLASS_$_FBSDKLoginManager", referenced from:
        objc-class-ref in SignUpViewController.o
        objc-class-ref in DataManager.o
        objc-class-ref in LoginViewController.o
    "_OBJC_CLASS_$_MGSwipeButton", referenced from:
        objc-class-ref in LessonsViewController.o
    "_OBJC_CLASS_$_MGSwipeTableCell", referenced from:
        _OBJC_CLASS_$_LessonTableViewCell in LessonTableViewCell.o
    "_OBJC_CLASS_$_Mixpanel", referenced from:
        objc-class-ref in AppDelegate.o
        objc-class-ref in InitialViewController.o
        objc-class-ref in DataManager.o
    "_OBJC_CLASS_$_WYPopoverController", referenced from:
        objc-class-ref in GuideViewController.o
    "_OBJC_METACLASS_$_MGSwipeTableCell", referenced from:
        _OBJC_METACLASS_$_LessonTableViewCell in LessonTableViewCell.o
  ld: symbol(s) not found for architecture x86_64
  clang: error: linker command failed with exit code 1 (use -v to see invocation)
  </code></pre>
  
  <p>Any help will be highly appreciated. I can debug, build and archive my project, if i do it on actual device but not on simulator. I have added all these frameworks via cocapods and i am using Xcode 7.3.</p>