I am unable to download and install the iOS Simulator runtime in Xcode 26.6. Environment: MacBook Air with Apple silicon macOS Tahoe 26.6 Xcode 26.6 Build version 17F113 xcode-select -p: /Applications/Xcode.app/Contents/Developer xcodebuild -showsdks correctly reports: Simulator - iOS 26.5 -sdk iphonesimulator26.5 However: xcrun simctl list runtimes returns: == Runtimes == No Simulator runtime is installed. In: Xcode > Settings > Components I attempted to install: iOS 26.5.1 + iOS 26.5 Simulator but it remains at: Preparing... for a very long time without actually downloading the runtime. I also tried: xcodebuild -downloadPlatform iOS This eventually failed with: Download was cancelled exit code 70 I also tried: xcodebuild -downloadPlatform iOS -exportPath ~/Downloads/XcodePlatforms The destination directory remains at 0 bytes. Checks already completed: More than 860 GiB free disk space Mac restarted Xcode quit and reopened xcode-select points to the correct Xcode installation /etc/hosts contains no Apple blocking entries gdmf.apple.com resolves correctly HTTPS connectivity to gdmf.apple.com works Apple MobileAsset / software update services are running iOS Simulator SDK itself is installed correctly The project can compile for iphonesimulator26.5, but Simulator execution and tests are blocked because no runtime can be installed. Questions: Is this a known issue with Xcode 26.6? Is there an official alternative way to download the iOS Simulator runtime? Can I install an earlier supported iOS Simulator runtime instead? Is there a MobileAsset or Xcode cache reset procedure recommended by Apple? Thank you.