While trying to run the simulator with iOS 11 in Xcode 10 Version 10.1 (10B61), sometimes this error occurs:
"The com.apple.CoreSimulator.SimRuntime.iOS-11-4 simulator
runtime is not available.
runtime profile not found"
The 11.4 simulator runtime is an external disk and it's well connected. Maybe that happens when I connect the external disk after opening the Xcode. How can I refresh the list of the available simulator runtime profiles?
Just run
sudo killall -9 com.apple.CoreSimulator.CoreSimulatorService
to restart the Simulator service.
来源：https://stackoverflow.com/questions/53261256/xcode-10-simulator-runtime-is-not-available-runtime-profile-not-found-error