Error MT0091: This version of Xamarin.iOS requires the iOS 11.1 SDK (shipped with Xcode 9.1). Either upgrade Xcode to get the required header files or set the managed linker behaviour to Link Framework SDKs Only (to try to avoid the new APIs). (MT0091) (XMvvmAPI.iOS)
을 모두 MAC 용으로 업데이트되었습니다. 그러나 아직도오고있다.
Xcode를 업데이트하셨습니까? – SushiHangover