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 follow error in Xcode: Cannot Preview in this file. Simulator was shutdown during an update. I have tried the following: Uninstall Xcode and reinstall it again 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" I reported the issue: FB20485454 FB20987522 Thank you. Best regards, Jens

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'm attempting to install a previously downloaded .xcappdata to my running application on the iPadOS Simulator (running iPadOS 26.1), but the app data won't transfer to the simulator. I've created the Xcode basic iPadOS app template, without any code modifications - adding some items to the list and downloading the .xcappdata from an attached iPad (running iPadOS 26.1). I can remove the app from the iPad and re-attach the .xcappdata to the physical iPad - no issues there. The issues I'm having is when trying to attach the app data on a simulator. Steps I've tried: Manually drag and dropping the .xcappdata file to the simulator. I get a popup saying "Simulator device failed to install application data container." Attaching the .xcappdata through Xcode in the "Edit Schemes"->Options->App Data App starts fresh without any errors or items from the .xcappdata file Installing the .xcappdata file through the command line through xcrun simctl install_app_data <SIM_DEVICE_ID> <MY_XCAPPDATA> This gives an error: Simulator device failed to install application data container. Could not get the existing data container location for the app. Container manager error code: 55 Underlying error (domain=com.apple.containermanager, code=55): Failed to install the requested app data package Could not get the existing data container location for the app. Container manager error code: 55 I can however reach the "data container location" through the xcrun simctl get_app_container command, leading me to think there are some issues with underlying permissions?

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.

CRITICAL: iOS 26.1 Simulator Runtime (Build 23B86) Missing / MobileAsset Catalog Failing Summary After updating macOS and Xcode, I can no longer download or install the required iOS 26.1 simulator runtime. The Xcode Components system fails for all assets, and the MobileAsset catalog for iOS simulator runtimes appears to be missing or invalid. The runtime is also not listed on developer.apple.com. This issue blocks me from running any iOS simulators. Steps to Reproduce Update to: macOS 26.1 (25B78) Xcode 26.1.1 (24455 / 17B100) Open Xcode → Settings → Platforms/Components Attempt to download: iOS 26.1 Simulator Runtime Any other downloadable component (e.g., Predictive Code Completion Model) Alternatively, try using: xcodebuild -downloadPlatform iOS -exportPath ~/Downloads xcodebuild -downloadPlatform iOS -buildVersion 26 Observed Behaviour Xcode Components Downloads Fail Attempting to download the iOS 26.1 runtime results in: Download failed. Domain: DVTDownloadableErrorDomain Code: 41 Additional detail: Failed fetching catalog for assetType (com.apple.MobileAsset.iOSSimulatorRuntime) Domain: DVTDownloadsUtilitiesErrorDomain Code: -1 And: Download failed due to a bad URL. Domain: com.apple.MobileAssetError.Download Code: 49 User Info: { checkConfiguration = 1 } Predictive Code Completion Model Also Fails The operation couldn’t be completed. (IDELanguageModelKit.IDEModelDownloadAdapter.DownloadError error 2.) Domain: IDELanguageModelKit.IDEModelDownloadAdapter.DownloadError Code: 2 There was an error transferring over the network. Code: 2 CLI Downloads Fail Command: xcodebuild -downloadPlatform iOS -exportPath ~/Downloads Result: DVTDownloadable: Download Failed … iOS 26.1 Simulator (23B86) Command: xcodebuild -downloadPlatform iOS -exportPath ~/Downloads -buildVersion 26 Result: iOS 26 is not available for download. Runtime Not Listed on Developer Downloads The following page does not list iOS 26.1 simulator runtime: https://developer.apple.com/download/all/ Expected Behaviour Xcode should be able to fetch the MobileAsset catalog and download iOS 26.1 simulator runtime. The runtime should appear in the Components tab and on developer.apple.com/download/all/. CLI tools should successfully download the platform. System Information macOS: 26.1 (Build 25B78) Xcode: 26.1.1 (24455) (Build 17B100) Timestamp: 2025-11-17 Impact This issue currently prevents: Running any iOS simulator Testing or building on the required runtime Using other Xcode downloadable components (language models, etc.) This is a blocking issue for development. Notes Multiple Xcode reinstallations attempted macOS restarts performed Network connectivity normal Issue persists across all download methods (GUI + CLI)

I have a small, simple iOS project that doesn't use a lot of memory or libraries or anything. If I open my iOS project in XCode and run it on the iPhone 17 simulator, my memory consumption (as seen in Activity Monitor) goes into the yellow zone. Granted, I have some other apps open (Safari, Mail, Messages, the usual stuff that people run) but nothing especially demanding. Without XCode and the Simulator running, my memory consumption is only around 25% on the Activity Monitor graph. Is this expected behavior with Tahoe and iOS 26? I was able to work on my project without running out of RAM on this same computer for the past 4 years no problem. Now it seems I have a problem.

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!

This is a M4 iMac 32GB 2TB where over the last few months memory use has been crazy. The worst offender is SimulatorTrampoline. I just opened a default iOS app and ran it in a simulator. So this is as simple as it gets: there's 1 SF Symbol and "Hello, world!" text. iStatMenus shows SimulatorTrampoline at 10.7GB, Safari 5.2GB, Xcode at 3.2GB, and swap at 548MB meanwhile ActivityMonitor shows the top memory use of Ildb-rpc-server at 2.30GB, Xcode at 523.4MB Swap is 548MB is the only number that matches and the fact that Memory used is ~26GB total. Is this amount of memory use normal? Is iStat menu reporting something different than Activity monitor. This computer used to never swap. Any suggestions?

Currently Xcode has iOS simulators that allow easily testing apps on older versions of iOS. It would be helpful if there was also a macOS simulator for testing apps on older versions of macOS. FB21229682 https://github.com/feedback-assistant/reports/issues/724

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!

There are multiple iOS simulator runtimes located at /System/Library/AssetsV2/com_apple_MobileAsset_iOSSimulatorRuntime which I don't need. I tried the following approaches to delete them but not working. Xcode > Settings > Components > Delete (It can delete some but not all of them) xcrun simctl runtime list (It doesn't show the old runtimes) sudo rm (Operation not permitted) sudo rm -rf cc1f035290d244fca4f74d9d243fcd02d2876c27.asset Password: rm: cc1f035290d244fca4f74d9d243fcd02d2876c27.asset/AssetData/096-69246-684.dmg: Operation not permitted rm: cc1f035290d244fca4f74d9d243fcd02d2876c27.asset/AssetData: Operation not permitted rm: cc1f035290d244fca4f74d9d243fcd02d2876c27.asset/Info.plist: Operation not permitted rm: cc1f035290d244fca4f74d9d243fcd02d2876c27.asset/version.plist: Operation not permitted rm: cc1f035290d244fca4f74d9d243fcd02d2876c27.asset: Operation not permitted I have two questions: Why "xcrun simctl runtime list" is unable to list some old runtimes? How to delete them?

Hello, I was wondering what simulator device is the Xcode Playground tested on? Is it better to support all screen sizes (e.g. IPads, IPhones..etc) and different orientations? Thanks!

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 trying to download an iOS Simulator runtime in Xcode 26.2 or 26.1 on macOS 26.1, but the download keeps failing with the following error: Download failed. Domain: DVTDownloadableErrorDomain Code: 41 Failed fetching catalog for assetType (com.apple.MobileAsset.iOSSimulatorRuntime), serverParameters ({ RequestedBuild = 23C54;}) Domain: DVTDownloadsUtilitiesErrorDomain. Code: -1. Download failed due to a bad URL. (Catalog download for com.apple.MobileAsset.iOSSimulatorRuntime) Domain: com.apple.MobileAssetError.Download Code: 49 User Info: {checkConfiguration = 1;} macOS &amp; Xcode Info: macOS Version: 26.1 (Build 25B78) Xcode Version: 26.2 (24553) (Build 17C52) What I've tried so far: Formatted my Mac and reinstalled Xcode multiple times. Completely deleted Xcode and its related files several times (/Applications/Xcode.app, caches, preferences). Tried different internet connections from multiple locations. Checked Apple servers and verified network. Attempted downloading other simulator runtimes (fail). but download fails immediately with DVTDownloadableErrorDomain Code 41 and bad URL error. Question: How can I fix the simulator download issue in Xcode 26.2 on macOS 26.1? Is there a known workaround for the bad URL / catalog download error?

I've been going through different fixes for a few weeks and nothing seems to work. Prior to updating everything to iOS 26 and OS 26, everything worked normally except for the predictive code which wouldn't download. Download failed. Domain: DVTDownloadableErrorDomain Code: 41 User Info: { DVTErrorCreationDateKey = "2026-01-02 23:41:12 +0000"; } Download failed. Domain: DVTDownloadableErrorDomain Code: 41 Failed fetching catalog for assetType (com.apple.MobileAsset.iOSSimulatorRuntime), serverParameters ({ RequestedBuild = 23C54; }) Domain: DVTDownloadsUtilitiesErrorDomain Code: -1 Download failed due to a bad URL. (Catalog download for com.apple.MobileAsset.iOSSimulatorRuntime) Domain: com.apple.MobileAssetError.Download Code: 49 User Info: { checkConfiguration = 1; } System Information macOS Version 26.0 (Build 25A354) Xcode 26.2 (24553) (Build 17C52) Timestamp: 2026-01-02T16:41:12-07:00 What I've Tried Cleared caches Restarted my machine Reinstalled Xcode Installed other versions of Xcode Installed Xcode-beta Using a VPN Not using a VPN Changing DNS settings Using a different Wifi network Using an older machine Using an older OS I've run out of options and I have no idea what else to do. The issue every time seems to point back to Apple servers.

👋Hi This problem is related to SSC. I remember that the form submitted last year needed to be filled in with Xcode or Playground test, and it seems that it was also mentioned: • If you use Xcode, the judges may use Simulator to run. • If you use Playground, it's a real machine. But my work this time will encounter two limitations: It will use the framework/API only available in iPadOS 26 (so if it is a Playground environment, it may not run, playground can't use iPadOS 26 SDK) It will also use some content that must be real to run (such as ARKit), which means that Xcode Simulator is not good. So I would like to ask: Does this year's review allow you to compile and connect the iPad to the real machine? Or did I misremember last year's regulations? If the judge's environment is fixed (for example, only Playground or only Simulator), how should I adjust the submission method or implement the scheme? Looking forward to your reply, thank you.

I’m using macOS Tahoe 26, and Xcode is version 26.2. I’ve tried all the methods suggested online, but I still can’t download it. In addition, iOS 26.* and iOS 18.* simulators also fail to download. The error messages are shown below. Download failed. Domain: DVTDownloadableErrorDomain Code: 41 User Info: { DVTErrorCreationDateKey = "2026-01-06 01:25:11 +0000"; } Download failed. Domain: DVTDownloadableErrorDomain Code: 41 Failed fetching catalog for assetType (com.apple.MobileAsset.iOSSimulatorRuntime), serverParameters ({ RequestedBuild = 23C54; }) Domain: DVTDownloadsUtilitiesErrorDomain Code: -1 Download failed due to a general networking error. (Catalog download for com.apple.MobileAsset.iOSSimulatorRuntime) Domain: com.apple.MobileAssetError.Download Code: 47 User Info: { tryAgainLater = 1; } System Information macOS Version 26.0 (Build 25A354) Xcode 26.2 (24553) (Build 17C52) Timestamp: 2026-01-06T09:25:11+08:00

Hi everyone, I'm experiencing a persistent issue for months now where I'm unable to download the iOS 26 simulator Runtime. I've tried reinstalling Xcode and also Xcode Beta but same issue. iOS 26 Simulator is also not on developers download page, so manual installation is impossible. And sadly I can't compile any code without having iOS 26 simulator installed. Anyone able to get passed this? Hardware: M1 Pro OS: Tahoe 26.1 Heres the error Download failed. Domain: DVTDownloadableErrorDomain Code: 41 User Info: { DVTErrorCreationDateKey = "2026-01-07 11:35:35 +0000"; } -- Download failed. Domain: DVTDownloadableErrorDomain Code: 41 -- Failed fetching catalog for assetType (com.apple.MobileAsset.iOSSimulatorRuntime), serverParameters ({ RequestedBuild = 23C54; }) Domain: DVTDownloadsUtilitiesErrorDomain Code: -1 -- Download failed due to not being able to connect to the host. (Catalog download for com.apple.MobileAsset.iOSSimulatorRuntime) Domain: com.apple.MobileAssetError.Download Code: 60 User Info: { checkNetwork = 1; } -- System Information macOS Version 26.1 (Build 25B78) Xcode 26.2 (24553) (Build 17C52) Timestamp: 2026-01-07T12:35:35+01:00

Prior to iOS 26.0 we were able to download specific simulator runtimes from the command line by using a command like xcodebuild -downloadPlatform iOS -buildVersion 18.0 This is described in the documentation here. This no longer works for 26.x. If I run the following command: "xcodebuild -downloadPlatform iOS -buildVersion 26.0" it fails with the following error: "Finding content... iOS 26.0 is not available for download." If I omit the -buildVersion flag it will download the latest version, currently 26.2, but if I try and specify 26.2 as the buildVersion I still get "iOS 26.2 is not available for download". This behavior has been confirmed on Xcode 26.2. Perhaps related, it appears these runtimes are also no longer being made available for download on https://developer.apple.com/download/all

When I have a TextField or TextEditor, tapping into it produces these two console entries about 18 times each: CHHapticPattern.mm:487 +[CHHapticPattern patternForKey:error:]: Failed to read pattern library data: Error Domain=NSCocoaErrorDomain Code=260 "The file “hapticpatternlibrary.plist” couldn’t be opened because there is no such file." UserInfo={NSFilePath=/Library/Audio/Tunings/Generic/Haptics/Library/hapticpatternlibrary.plist, NSURL=file:///Library/Audio/Tunings/Generic/Haptics/Library/hapticpatternlibrary.plist, NSUnderlyingError=0x600000ca1b30 {Error Domain=NSPOSIXErrorDomain Code=2 "No such file or directory"}} <_UIKBFeedbackGenerator: 0x600003505290>: Error creating CHHapticPattern: Error Domain=NSCocoaErrorDomain Code=260 "The file “hapticpatternlibrary.plist” couldn’t be opened because there is no such file." UserInfo={NSFilePath=/Library/Audio/Tunings/Generic/Haptics/Library/hapticpatternlibrary.plist, NSURL=file:///Library/Audio/Tunings/Generic/Haptics/Library/hapticpatternlibrary.plist, NSUnderlyingError=0x600000ca1b30 {Error Domain=NSPOSIXErrorDomain Code=2 "No such file or directory"}} My app does not use haptics. This doesn't appear to cause any issues, although entering text can feel a bit sluggish (even on device), but I am unable to determine relatedness. None-the-less, it definitely is a lot of log noise. Code to reproduce in simulator (xcode 26.2; ios 26 or 18, with iPhone 16 Pro or iPhone 17 Pro): import SwiftUI struct ContentView: View { @State private var textEntered: String = "" @State private var textEntered2: String = "" @State private var textEntered3: String = "" var body: some View { VStack { Spacer() TextField("Tap Here", text: $textEntered) TextField("Tap Here Too", text: $textEntered2) TextEditor(text: $textEntered3) .overlay(RoundedRectangle(cornerRadius: 8).strokeBorder(.primary, lineWidth: 1)) .frame(height: 100) Spacer() } } } #Preview { ContentView() } Tapping back and forth in these fields generates the errors each time. Thanks, Steve