Some Macs recently received a macOS system update which disabled the simulator runtimes used by Xcode 15, including the simulators for iOS, tvOS, watchOS, and visionOS. If your Mac received this update, you will receive the following error message and will be unable to use the simulator: The com.apple.CoreSimulator.SimRuntime.iOS-17-2 simulator runtime is not available. Domain: com.apple.CoreSimulator.SimError Code: 401 Failure Reason: runtime profile not found using "System" match policy Recovery Suggestion: Download the com.apple.CoreSimulator.SimRuntime.iOS-17-2 simulator runtime from the Xcode To resume using the simulator, please reboot your Mac. After rebooting, check Xcode Preferences → Platforms to ensure that the simulator runtime you would like to use is still installed. If it is missing, use the Get button to download it again. The Xcode 15.3 Release Notes are also updated with this information.

My swift student challenge submission is an iPad app built in Xcode and I'm planning on selecting the Xcode 26 option for testing in the dropdown provided in the application. Just have to confirm that the run destination for the playground in Xcode will be an iPad simulator right? Recently I have seen many participants post their submission screenshot for iPhone renders so just wanted to confirm the run destination. Thank you👾

Hi, I was wondering if there’s a way to ensure my submission is tested on an iPad simulator in Xcode as some UI elements were designed with a large display in mind ?

Hi, I’m facing a consistent simulator boot issue that appears to start after iOS 18.2 simulator runtimes and persists in 18.6, 26.1, and 26.2. Observed behavior iOS 18.2 simulator works fine iOS 18.6 simulator does NOT boot iOS 26.1 / 26.2 simulators do NOT boot Tried everything reinstall/clear cache and all and event formatted the system Unable to boot the Simulator NSPOSIXErrorDomain Code: 4 Failure Reason: Interrupted system call Failed to start launchd_sim: could not bind to session, launchd_sim may have crashed or quit responding macOS: Sequoia Xcode: 26.1, 26.2 Machine: Apple Silicon Unable to boot the Simulator. Domain: NSPOSIXErrorDomain Code: 4 Failure Reason: Interrupted system call User Info: { DVTErrorCreationDateKey = "2025-12-26 02:19:27 +0000"; IDERunOperationFailingWorker = "_IDEInstalliP.honeSimulatorWorker", Session = "com apple CoreSimulator.SimDevice CCDECA56-4A59-491B-A830-0F3928FCD957"; } Failed to start launchd_sim: could not bind to session, launchd_sim may have crashed or quit responding Domain: com.apple.SimLaunchHostService.RequestError Code: 4 Event Metadata: com.apple. dt. DERunOperationWorkerFinished : { "device_identifier" = "CCDECAE6-4A59-491B-A830-0E3928FCD957"; "device_model" = "iPhone18, 1"; "device_osBuild" = "26.1 (23B86)"; "device_osBuild_monotonic" = 2301008600; "device_os_variant" = 1; "device_platform" = "com apple.platform.iohonesimulator"; "device_platform_family" = 2; "device_reality" = 2; "device_thinningType" = "iPhone18,1"; "device_transport" = 4; "launchSession_schemeCommand" = Run; "launchSession_schemeCommand_enum" = 1; "launchSession_targetArch" = arm64; "launchSession_targetArch_enum" = 6; "operation_duration_ms" = 1183; "operation_errorCode" = 4; "operation_errorDomain" = NSPOSIXErrorDomain; "operation_errorWorker" = "_IDEInstalliPhoneSimulatorWorker"; "operation_error_reportable" = 1; "operation_name" = IDERunOperationWorkerGroup; "param_consoleMode" = 1; "param_debugger_attachToExtensions" = 0; "param_debugger_attachToXPC" = 1; "param_debugger_type" = 3; "param_destination_isProxy" = 0; "param_destination_platform" = "com apple platform Please help on this as it got stuck. Thanks

I'm building an app which runs around the Foundation model framework. My expected output is generated when testing on a real device or in preview in Xcode but it throws Foundation Model error when I try running it on the simulator. I'm using a Macbook M1 air and have apple intelligence turned on and my simulator run destination is also an iPad Pro M5 (26.0). Any solution for this as this is my submission for the SSC so I need to make it work on the simulator iPad. Thank you👾

Hello, We are experiencing a recurring issue when running iOS apps in the Rosetta simulator on Xcode 26. Environment: Xcode: 26.0 macOS: 15.7.3 Simulator: Intel-based (Rosetta) simulators Languages: Both Swift and Objective-C Issue: When launching an app in a Rosetta simulator, the app frequently freezes or fails to run. In many cases, Xcode reports that the debugger has lost connection. Xcode error message: Lost connection to the debugger on “iPhone 12”. Domain: IDEDebugSessionErrorDomain Code: 22 Failure Reason: Message from debugger: lost connection Console log: assertion failed: GPR thread_set_state is unimplemented for NewThread (ThreadContextRegisterState.cpp:920 host_gpr_state_from_guest_state) Observed behavior: Rebuilding after fully quitting the simulator sometimes resolves the issue temporarily. Disabling Scheme > Run > Debug executable allows the app to run normally, but debugging (breakpoints, etc.) becomes unavailable. The issue does not occur: On real devices On ARM-based simulators When building with Xcode 16 using Rosetta Has anyone encountered this issue with Xcode 26 and Rosetta simulators? Is this a known bug, and are there any recommended workarounds besides disabling the debugger or restarting the simulator? Thank you in advance for any insights or guidance.

Following is an error I encounter when trying to run a foundation model function in simulator. Error Domain=FoundationModels.LanguageModelSession.GenerationError Code=-1 "(null)" UserInfo={NSMultipleUnderlyingErrorsKey=( "Error Domain=ModelManagerServices.ModelManagerError Code=1026 "(null)" UserInfo={NSMultipleUnderlyingErrorsKey=(\n)}" )} Its a swift playground I'm building in xcode and works fine in the preview and on a real device too but since it's my submission for the swift student challenge I need it to run on the simulator. I have updated my macOS to latest version of Tahoe(26.3) and Xcode is also on latest version. The simulator I run the playground is also on ios and iPadOS 26. I have set my region to US and have turned on Apple Intelligence on my mac too. Any suggestions on how to fix the issue?👾

Is it possible to run an xcode cloud test with arm64 simulators NOT x86? as my app doesnt work on x86.

Since one of the last updates of XCode, there are two very annoying bugs in the simulator that just don't get fixed. What's going on Apple? You kill my productivity. There is a red bar reading "rdar" and some numeric string at the top. You can get rid of it by going to Settings -> Developers -> Zoom -> Larger Text (then change it back). Took a while to find that. I have a German laptop with a QWERTZ keyboard layout. Now when I type, it somehow sends keys from an US keyboard to the simulator. Since I don't have the labels, I don't know what the hell I'm typing. Very frustrating. Please fix this.

Attempting to bring up the access point yields the following error log: [GameCenterOverlayService] Failed to create GameOverlayUI Dashboard Remote Proxy [GameCenterOverlayService] Could not create endpoint for service name: com.apple.GameOverlayUI.dashboard-service [GameCenterOverlayService] Failed to create GameOverlayUI Dashboard Remote Proxy [GameCenterOverlayService] Could not create endpoint for service name: com.apple.GameOverlayUI.dashboard-service [GameCenterOverlayService] Failed to create GameOverlayUI Dashboard Remote Proxy [GameCenterOverlayService] Failed to create GameOverlayUI Dashboard Remote Proxy The same code (which is a single line setting 'active' to true) works on physical devices and on the simulator in iOS 18.6 I haven't been able to find any mention of this issue online. Any suggestions or help greatly appreciated.

Hello, I am facing a recurring issue with Xcode iOS simulator (preview). I want to preview a SwiftUI for iOS in Xcode, but the Simulator app fails to boot up. I receive the following error in Xcode: Cannot Preview in this file. Simulator was shutdown during an update. I have tried the following: Completely uninstalling XCode and deleting all developer data, then reinstalling everthing again. Shutdown and restart Deleting all developer data, deleting XCode cache Reinstalling iOS Simulator runtimes and reconfiguration of simulators. Tested using different simulator and runtime versions. "xcrun simctl --set previews delete al" My reported issues: FB20987522 FB20485454 Thank you Best regards, Jens

I installed xcode 16 and both Predictive Code Completion Model and iOS 18.0 Simulator Failed Download. I can live without the code completion, but I can not get any Simulator to install. I clicked of the info button and it shows the following: Download failed. Domain: DVTDownloadableErrorDomain Code: 41 User Info: { DVTErrorCreationDateKey = "2024-09-30 15:57:24 +0000"; } Download failed. Domain: DVTDownloadableErrorDomain Code: 41 Failed fetching catalog for assetType (com.apple.MobileAsset.iOSSimulatorRuntime), serverParameters ({ RequestedBuild = 22A3351; }) Domain: DVTDownloadsUtilitiesErrorDomain Code: -1 Download failed as the server said authentication failed. (Catalog download for com.apple.MobileAsset.iOSSimulatorRuntime) Domain: com.apple.MobileAssetError.Download Code: 41 User Info: { checkServer = 1; } System Information macOS Version 15.0 (Build 24A335) Xcode 16.0 (23051) (Build 16A242d) Timestamp: 2024-09-30T10:57:24-05:00

I'm running Xcode 26.2 (17C52). After deleting all simulators and creating new ones, SwiftUI Preview stopped working. Xcode reports: “Simulator [D774B214-XXXX-XXXX-XXXX-XXXXXXXX8288] failed to boot and may have crashed.” However, when I list all available simulators using xcrun simctl list, there is no simulator with that identifier. It seems Xcode is still referencing a previously deleted simulator. I have tried: Deleting all simulators again Creating new simulators Restarting Xcode and the system But the issue persists and Preview still fails to launch. Has anyone encountered this issue or knows how to clear the cached simulator reference used by SwiftUI Preview?

Hello, I have a question about running tests on multiple simulators. Currently, my company has a WDIO+Appium test suite with XCUITEST driver that runs on a single simulator through a mockttp proxy (we are intercepting and mocking some of the responses from our APIs and pass through the rest). In order to route the traffic we are currently using 'networksetup -setsecurewebproxy '. Everything works as expected. With growing number of tests we'd like to scale number of simulators on a single host to 3-5. We have a working setup but the problem are system-wide proxy settings routing traffic from multiple simulators, which we can't distinguish by UDID or any other means, we know of. We can spin multiple mock servers on the same machine but we are struggling to find the way to route the traffic on a simulator basis. In the end, both options are viable: 1 mock server running for multiple simulators N number of mock servers for N number of simulators Has anyone had the same/similar problem? How to approach this? We are currently running on Sequoia OSX and platform version 18.6. Thanks!

When I use Xcode 26 (0.1, 1) for debugging and hit a breakpoint, using "step over" causes the debugger to freeze at a random line of code. Clicking "Pause program execution" indicates that the line is being executed, but the breakpoint never exits, seemingly causing a freeze. The application on the simulator also becomes unresponsive. However, when I do not use breakpoints, my program runs smoothly, and debugging on a physical device does not cause any freezes. This issue only occurs with the simulator. I am using Xcode on Apple Silicon, and due to some third-party SDKs that depend on Rosetta, our app can only run on the Rosetta simulator. We did not encounter this issue when using Xcode 16.x for simulator debugging. The current situation with Xcode 26.x significantly reduces our development efficiency. What could be causing this, and is there a solution?

When I start a Simulator (iPhone 13 mini) with iOS 26 and activate "Use the Same Keyboard Language as macOS", it still sets the keyboard to US (my Mac keyboard is in German). This makes the Mac keyboard unusable. It looks like a bug, because it clearly ignores the settings. When I type “@”, I get “¬”. Restarting the simulator did nothing, changing the settings back and forth also. BTW: Why does every single update of XCode come with a bug nowadays? I always have to spend half a day after an update to fix a problem I didn't have before. Highly frustrating.

Running the sample "Juice" app, which demos the Sign In With Apple flow, doesn't seem to work with Xcode 12 beta and iOS 14 beta on the simulator (worked fine on the non-beta versions and on a real device with iOS 14 beta). Once the password for the device's Apple ID is entered, the wheel in the password field just keeps spinning. No error messages and nothing handed back over to the app from the ASAuthorizationController. Anyone else seeing this problem ? Are there any workarounds ?

Hello, I created a code in Xcode on my Mac. Once it was debugged I tried to run it on a simulator. Every time I run it on a simulator I get the white screen with the spinning red box. I'm very new at this and I am creating this app for my own child. As a teacher I couldn't stand the other math fact apps. You'll have to talk to me like an infant.

Hello, Is there currently any workaround to install and run an iOS 14.x simulator on macOS 26? So far, I have checked Xcode 26.2, and the oldest simulator runtime available there appears to be iOS 15.0. I may be missing something, so I wanted to confirm if anyone has found a way to use iOS 14.x on this macOS version. Thank you.

Out of nowhere I got some red banner on top of my iPhone 13 mini / iOS 17.5. I cannot pin point the root cause of this. What I can say is that it only happens to Simulators of a certain type, e.g. iPhone 12 and 13 mini, but not iPhone 14 for example. I have installed Xcode 26.1.0 and 26.1.1, out of which 26.1.0 is selected: $ xcode-select -p /Applications/Xcode-26.1.0.app/Contents/Developer And following runtimes: $ xcrun simctl runtime list == Disk Images == -- iOS -- iOS 17.5 (21F79) - CF933623-A258-44F8-B248-C0F25C0C343B (Ready) iOS 26.1 (23B80) - D11C3CDC-EE3D-44CC-8B92-9B7D00B54B0B (Ready) Total Disk Images: 2 (14.6G) Installing the newer 26.1 23B86 runtime doesn't help either.

Hi everyone, I’m experiencing a persistent issue when trying to download the iOS Simulator Runtime 26.1 on Xcode (version 26.1). The download always fails with the following error Download failed due to a bad URL. (Catalog download for com.apple.MobileAsset.iOSSimulatorRuntime) Domain: com.apple.MobileAssetError.Download Code: 49 I’m located in Brazil, so I initially thought it might be region-related, but I’ve already tried several attempts to fix it, including: Using VPNs for the US and Europe Installing the Xcode 26.2 beta Downgrading Xcode to earlier versions Reinstalling the same version of Xcode Restarting Xcode and my Mac Switching networks Clearing simulator support/device files Unfortunately, nothing has resolved the issue. Is anyone else facing this problem? Does anyone know a workaround or a manual way to download/install the iOS 26.1 simulator runtime? Thanks in advance!