Simple solution: Open Xcode. Select the “Window” menu. Select “Devices and Simulators”. Select Simulators tab. Click on the “+” icon at the left bottom. Choose the desired device & preferred iOS. Click “Create”. Enjoy :).
In Xcode 9.1, go to Simulator Menu > Debug > Optimize Rendering for Window Scale. disable this option, now the screenshots will be in the right size (resolution).
Crashing on iOS 11 inside of CFNetwork
Please clear derived data folder (located at ~/Library/Developer/Xcode/DerivedData) and restart the Xcode project.
Keyboard cannot present view controllers warning