If you are unable to build and run your 4D for iOS app in simulator, check to see if you have the correct version of Xcode installed on your machine. Building and testing the mobile app both require Xcode to do so. If the "Build and Run" button is grayed out in the mobile app builder, the Xcode version may need to be updated.



Compatibility Table for 4D for iOS: https://developer.4d.com/4d-for-ios/docs/en/prerequisites.html