Hi,
I'm unable to download the iOS 18.5 (22F76) and iOS 18.6 (22G86) Simulator runtimes on macOS 15.6 (24G84). The issue persists across multiple versions of Xcode, including 16.4 (16F6) and Xcode 26 beta 3 (17A5276g).
Symptoms:
In Xcode > Settings > Platforms (Components tab), clicking “Get” for iOS 18.5 / 18.6 either does nothing or results in a download failure.
CLI command sudo xcodebuild -downloadPlatform iOS fails with:
Domain: DVTDownloadableErrorDomain, Code: 41
HTTP 403 Forbidden from Amazon S3/CloudFront
Switching to admin user, different networks, and clean reinstall of Xcode had no effect.
I also attempted manual installation using the .dmg files from the developer portal. After mounting (e.g. Xcode_15_Simulator_Runtime_iOS_18.2.dmg), I extracted iOS 18.2.simruntime, but Xcode does not recognize it.
File structure inside the extracted .simruntime:
Contents/
├── Info.plist (missing runtime identifier)
├── MacOS/
├── Resources/
└── _CodeSignature/
Expected structure (from working install):
Contents/
├── Info.plist (with runtime info)
├── RuntimeRoot/
├── Resources/
└── _CodeSignature/
Even copying a working .simruntime from another machine did not resolve the issue.
Additionally, in Xcode 26 beta 3 I received:
Download failed.
Domain: DVTDownloadableErrorDomain
Code: 41
Domain: com.apple.MobileAssetError.Download
Code: 60
Message: Download failed due to not being able to connect to the host. (Catalog download for com.apple.MobileAsset.iOSSimulatorRuntime)
This appears to be either a CDN-level or catalog configuration issue. Any guidance or workaround would be appreciated.
Thanks!
Please report the CDN error message through Feedback Assistant.
As to your manual addition steps, you don't need to do anything with the dmg file beyond downloading it. You can add it to the system by running xcrun simctl runtime add /Path/To/SimulatorRuntume.dmg in Terminal. Does that work, or do you get an error that way too?
— Ed Ford, DTS Engineer
