The strange thing is that is works just fine on an iPhone 5. But I get this error on iPhone 5s. The iOs version does not matter. I tested on iOS 7.0 and 7.1 on iPhone 5s and it still doesn't work.
2014-05-10 15:47:09.023 FitGoal[929:60b] FBLoginView encountered an error=Error Domain=com.facebook.sdk Code=2 "The operation couldn’t be completed. (com.facebook.sdk error 2.)" UserInfo=0x178264900 {com.facebook.sdk:ErrorLoginFailedReason=com.facebook.sdk:UserLoginCancelled, com.facebook.sdk:ErrorSessionKey=<FBSession: 0x178115450, state: FBSessionStateClosedLoginFailed, loginHandler: 0x0, appID: 676311875766710, urlSchemeSuffix: , tokenCachingStrategy:<FBSessionTokenCachingStrategy: 0x170010230>, expirationDate: (null), refreshDate: (null), attemptedRefreshDate: 0001-12-30 00:00:00 +0000, permissions:(null)>}
I got this error on another iPhone 5s as well:
2014-05-09 18:03:27.996 FitGoal[11685:60b] FBLoginView encountered an error=Error Domain=com.facebook.sdk Code=2 "The operation couldn’t be completed. (com.facebook.sdk error 2.)" UserInfo=0x17826dc80 {com.facebook.sdk:ErrorLoginFailedReason=com.facebook.sdk:SystemLoginError, com.facebook.sdk:ErrorInnerErrorKey=Error Domain=com.apple.accounts Code=7 "The Facebook server could not fulfill this access request: Invalid application 676311875766710" UserInfo=0x17826d800 {NSLocalizedDescription=The Facebook server could not fulfill this access request: Invalid application 676311875766710}, com.facebook.sdk:ErrorSessionKey=<FBSession: 0x178107230, state: FBSessionStateClosedLoginFailed, loginHandler: 0x0, appID: 676311875766710, urlSchemeSuffix: , tokenCachingStrategy:<FBSessionTokenCachingStrategy: 0x17801e7b0>, expirationDate: (null), refreshDate: (null), attemptedRefreshDate: 0001-12-30 00:00:00 +0000, permissions:(null)>}