SDK Version Issue. This app was built with the iOS 12.0 SDK. All iOS apps submitted to the App Store must be built with the iOS 11 SDK or later, included in Xcode 9 or later. Further, starting March 2019, all iOS apps submitted to the App Store must be built with the iOS 12.1 SDK or later, included in Xcode 10.1 or later.
翻译过来就是:
SDK版本问题。本应用程序是使用iOS 12.0 SDK开发的。所有提交到App Store的iOS应用程序都必须使用ios11或更高版本的SDK构建,包括Xcode 9或更高版本。此外,从2019年3月开始,所有提交到App Store的iOS应用程序都必须使用iOS 12.1或更高版本的SDK构建,包括Xcode 10.1或更高版本。