Xcode: simulator runtime is not available
Check the selected Xcode version, installed platform components, and simulator destination.
The selected simulated device needs a compatible runtime. Check Xcode’s installed Components, install or reinstall the required platform runtime, and choose a destination supported by the active Xcode version.
Try these fixes in order
Identify the requested runtime
Read the platform and OS version in the error, then check which Xcode app is open. If multiple Xcode versions are installed, the active app and command-line developer directory may differ.
Inspect installed components
Open Xcode Settings > Components and check whether the required simulator runtime is installed. Xcode may also offer a Get button next to the unavailable platform destination. Download the matching component from Xcode.
Select an available destination
Open the run destination menu and choose a simulator whose OS runtime is installed and supported by your project. If a team workflow needs the older destination, install that supported runtime rather than silently changing test coverage.
Restart after a component change
Quit and reopen Xcode after installation. If a macOS update has left a runtime unavailable, reboot the Mac and recheck Components before removing any simulator data.
Interpret what you see
The destination is listed as unavailable
What it suggests: A simulator device refers to a runtime not installed in the active Xcode.
Next check: Check Platforms in Xcode settings and install a compatible runtime before recreating the device.
Another Xcode installation can run it
What it suggests: The active developer directory and its runtimes differ between the two installations.
Next check: Compare the selected Xcode in settings or xcode-select with the one used by the build command.
The runtime exists but the app cannot launch
What it suggests: The failure has moved past runtime availability.
Next check: Read the CoreSimulator or app launch log instead of repeating platform downloads.
Why this happens
- The runtime for that simulated OS was never installed or is unavailable to this Xcode.
- A macOS or Xcode update changed component availability.
Still not working?
Avoid deleting simulator devices or DerivedData as the first step. Preserve simulator data if it matters; record the Xcode build number, macOS version, runtime version, and full CoreSimulator error for Apple support.
Official sources
- Apple: install additional Xcode components ↗
- Apple: run on simulated devices ↗
- Apple: Xcode platform components ↗
These steps are based on the linked documentation and general diagnostics. BugMedic has not independently tested every product and system configuration. Review commands before running them.