When I upload my app using Xcode 9 to AppStore, received this error message :
iTunes Store Operation Failed
WARNING ITMS-90725: "SDK Version Issue. This app was built with the iOS 11.2 SDK. 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."
I understand that message, but I do not understand why it is rejected. I uploaded on Dec 14, 2018, while the error message stated it will be on March 2019.
Do I need to update Xcode ? I'm still using macOS Sierra 10.12.6, Xcode 9.x.