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.
Simulator
RSS for tagRapidly prototype and test builds of your app during the development process using Simulator.
Posts under Simulator tag
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Hi everyone,
I’m an iOS developer working on a Mac with limited storage (256 GB).
I’ve noticed that the ~/Library/Developer folder is taking up almost 90 GB, mainly due to Xcode-related content.
Inside it I see folders like:
Xcode/DerivedData
DocumentationCache
iOS DeviceSupport
UserData
CoreSimulator/Devices
Before deleting anything, I’d like to understand which of these folders are safe to clean up, and what the potential side effects might be (for example, rebuild times, simulator re-downloads, etc.).
What is the recommended best practice to manage disk space when using Xcode on a low-storage machine?
Thanks in advance for your help.
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
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
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.
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
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
I'm unable to reset simulators using the menu or the xcrun simctl tool:
<output of xcrun simctl list>
== Devices ==
-- iOS 17.5 --
iPhone SE (3rd generation) (5A06623A-173D-4C96-8DD3-3E9FE39A06F1) (Shutdown)
iPhone 15 (iOS 17.5) (F4329E8D-29BB-4EA7-8465-C11A98D04ED7) (Shutdown)
-- iOS 18.0 --
iPhone SE (3rd generation) (2DDE8F03-F8E1-4C1B-8E28-CD9B208F3FFA) (Shutdown)
iPhone 16 Pro (DE788688-8AC6-40A0-B25C-A56AA423798E) (Shutdown)
iPhone 16 Pro Max (1405184C-36A9-40F3-B0D0-4EEB88452883) (Shutdown)
iPhone 16 (0CBBA7DB-B20E-4F17-BBC5-910F1F6E1A0A) (Shutdown)
iPhone 16 Plus (95421C27-11A0-4FCF-A889-DAAE8557B271) (Shutdown)
== Device Pairs ==
~/Library``
❯ xcrun simctl erase 0CBBA7DB-B20E-4F17-BBC5-910F1F6E1A0A
An error was encountered processing the command (domain=NSCocoaErrorDomain, code=513):
“data” couldn’t be moved because you don’t have permission to access “Deleting-8FEDFF47-5B2F-4534-BCA2-036BBE68CE37”.
You don’t have permission.
To view or change permissions, select the item in the Finder and choose File > Get Info.
Underlying error (domain=NSPOSIXErrorDomain, code=1):
The operation couldn’t be completed. Operation not permitted
Operation not permitted
Xcode Version 16.0 (16A242d)
MacOS 15.0.1 (24A348)
👋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.
Topic:
Community
SubTopic:
Swift Student Challenge
Tags:
Swift Student Challenge
Swift Playground
iPadOS
Simulator
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 & 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?
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!
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
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!
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.
My app uses SwiftUI Map and draws Markers, MapPolyline and MapPolygons over it. These all work on actual devices. On the iOS 26.0.1 Simulator running on macOS 26.0.1 Polylines and Polygons do now show.
Do others see the same thing?
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?
[Submitted as FB20950954]
Xcode Simulator causes crackling and distortion in audio playback across all apps (Apple Podcasts, Music, third-party).
REPRO STEPS
Open any audio app and start playback
Note the audio quality
Launch Xcode Simulator
After a few seconds, note audio quality again
Quit Xcode Simulator
Audio returns to normal
CURRENT
Audio has crackling and distortion while Simulator is running.
EXPECTED
Clean audio playback regardless of whether Simulator is running.
SYSTEM INFO
macOS 26.1 (25B78)
Xcode 26.1 (17B55)
Simulator 26.0 (1058)
In previous versions of the simulator, it was possible to import files into the Files app by dragging them from the Finder into the Simulator. It appears that in the iOS 26 Simulator, this opens the file in Safari.
I've only tried it with .json files so far.
The documentation at https://developer.apple.com/documentation/xcode/sharing-data-with-simulator says that the original behaviour should happen:
To add files to Simulator, select one or more files in Finder on your Mac, then click the Share button. Select Simulator from the share destination list. Choose the simulated device from the drop-down list. Simulator opens the Files app, and lets you select where to save the files.
I'd love to learn if this is intentional behaviour, and if so, what workarounds there might be. I use this pattern quite a lot, as I have a HealthKit app, and I've built a system that allows me to export workouts as JSON files from a real device, that I can then import into a simulator for testing.
Edit: I found a workaround. Make a folder in Files.app, then search for it within ~/Library/Developer/CoreSimulator/Devices. Open the folder in Finder, then add any files you want to be available in the Simulator.
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!
Hi, We are trying to use Apple Security API for KeyChain Services. The motive is to store some sensitive data in the KeyChain. Our app has Network extensions enabled which share a common app group and we want to access the data stored in the KeyChain from the extensions as well. Specifically we were exploring the SecItemAdd, SecItemCopyMatching etc family of APIs. We tried a few methods:
Using the common App Group : Specifying the common app group in the "kSecAttrAccessGroup" field of the KeyChain query, allowed us to have a shared keychains for different apps (targets) in the app group, but this did not work for extensionsEnabling the KeyChain Sharing capability : We enabled the KeyChain Sharing Ability in the extensions and the app target as well, giving a common KeyChain Access group. Specifying this in the kSecAttrAccessGroup field also did not work.We tried specifying "$AppIdentifier.KeyChainSharingGroup" in the kSecAttrAccessGroup field , but this did not work as wellThe error code which we get in all these 3 cases when trying to access the Keychain from the extension is error code 25291 (errSecNotAvailable). The Documentation says this error comes when "No Trust Results are available" and printing the error in xcode using the status says "No keychain is available. You may need to restart your computer". The online Documentation says that it is possible to share keychain with extensions, but by far we are unable to do it with the methods suggested.Do we need any special entitlement for this or is there something we are missing while using these APIs?If this is possible Is there any internal/open source wrapper for Keychain APIs, that we can use?We will really appreciate help in solving this issue!Thanks!
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