I'm running in a very very very weird error. I have a large asset catalog, consisting of about 2700 assets for 1.19GB of size. I can successfully build and run my project with both release and debug scheme, when a real device or simulator is selected. However, whenever I select Any iOS device (arm64), about 80ish seconds in the build process, the building fails with the following output: CoreUI: Error: unable to add asset to store *** Terminating app due to uncaught exception 'IBPlatformToolFailureException', reason: 'The tool closed the connection (AssetCatalogSimulatorAgent) What I tried and failed: Cleaning DerivedData and restarting PC Building the same project on three different devices, each with a different version of XCode. All failed. running sudo killall -9 com.apple.CoreSimulator.CoreSimulatorService Scanning for duplicate image files, found none. Scanning for duplicate .imageset folders in different folders, found none. Scanning for images that declared a different format than theirs, eg .webp renamed as .png, and found none. Creating an empty Hello World project, and just adding my asset catalog. Build fails for Any iOS device, succeeds for simulator or physical device. Uninstalling and reinstalling XCode command line tools. Manually compiling via actools. Changed "Embed Assets Pack in Product Bundle" from No to Yes. I don't have any .svg file in my assets. What I tried and failed but gives more insight: Now the only thing that I was able to come up with was deleting folders to narrow down where the problem was. So I found that there is a 700MB folder called T, containing T1, T2, ..., T6. Eventually managed to narrow down even more to T3, T4, T6. I created a distinct .xcassets catalog for each subfolder and tried to compile individually with actools, along with assets.xcassets (the main one). Here's the thing: T3.xcassets + assets.xcassets compiles T4.xcassets + assets.xcassets compiles T6.xcassets + assets.xcassets compiles T3.xcassets + T4.xcassets + assets.xcassets compiles. T3.xcassets + T6.xcassets + assets.xcassets compiles. T4.xcassets + T6.xcassets + assets.xcassets compiles. T3.xcassets + T4.xcassets + T6.xcassets + assets.xcassets crashes with CoreUI: Error: unable to add asset to store. I've been stuck for days now and can't deploy my finished app I worked on for the last three years because of this.

After changing Xcode 16.2 with min iOS 15. I got error in debug mode Assertion failed: (reconstituted == accumulator), function setFixup64, file OutputFile.cpp, line 2975. But project still can archive to IPA. Anyone has the same issue as me?

My Xcode version is 16.4, I have added an old version simulator (iPhone 13 with iOS 17.2) to the simulator list, but I can't use it for debugging, and all on display are iPhone 16 with 18.6 (the latest iOS devices). The setting "Minimum Deployments" for my App is 16.6. In addition, when I downloaded an iOS 16.0 version simulator, Xcode automatically added all iPhone 15 models of the simulator, but I still can't use them. In short, I can only use the default iPhone 16 simulators. So, if I want to debug my App using iPhone 13 (iOS 17.2), what should I do? Thank you for your reply. :) Another small issue, my App's destination has been set to support only iPhone, why are those iPad simulators still appearing?

Hey guys, I updated to macOS Tahoe and after that I tried installing Xcode 26, but I always get an error message saying it can’t complete the installation, both through the App Store and via direct download from Apple’s website. Is anyone else having this same issue?

Whenever I hit play on my app to test it on the Mac the register .app part starts taking more than 15 minutes, this is severely impacting my work. There's no indication on what's wrong and how can I fix this.

I'm unable to debug on iPhone 12 running iOS 17 beta 3 via network. I'm running Xcode 15 beta 6 Device shows in devices and simulators and I can debug when connected with cable. However the "Connect Via Network" option is frayed out, oddly however the checkbox is ticked I'm developing a app using RoomPlan so network connectivity is a must for debugging Anyone else encountered this and know how to get around this problem Other devices running iOS 16 connect via network just fine

With Xcode 26.0 beta 5 (17A5295f) when I run the following command xcodebuild -downloadComponent metalToolchain I get the following error: xcodebuild[48851:12478851] Writing error result bundle to /var/folders/b_/g67r_tl557z244g20ncr_qmsd9wrz1/T/ResultBundle_2025-07-08_11-10-0012.xcresult xcodebuild: error: Failed fetching catalog for assetType (com.apple.MobileAsset.MetalToolchain), serverParameters ({ RequestedBuild = 17A5295f; }) I can't install the toolchain from the Xcode GUI also. Does someone know a workaround ?

Hi! I'm having problems installing the iOS 18.4 SDK for Xcode. The installation fails from within Xcode or from the command line with the following error message: $ xcodebuild -downloadPlatform iOS Downloading iOS 18.4 Simulator (22E238): Preparing to download...2025-04-05 10:16:50.451 xcodebuild[7138:103696] DVTDownloadable: Observed finish. Cancelling download asset. { assetId = 6fb1e5fe25ee1c372f7116516e615c556906bd4e; assetIdHash = 9d684dee0a7bae81ba9c4f79475976f41789eaf3; assetType = "com.apple.MobileAsset.iOSSimulatorRuntime"; attributesHash = 99e0653b3c175e32d4a045cb9be856573b2938c1; contentHash = d4aad730490a4476d8179d4cdb7c1fcae8dd388a; nonIdHash = be7dd5950580ff7c8e1f822b24bd76d58c08b8aa; pallasDynamicAssetIdHash = d7904ac1d93cc3702244074c49aafad923a6e2b4; policyHash = d3700ca0e5058eb1d7b21fd74b1c225a66f5e74e; urlHash = fc93246f74e44ae2b94a727bfd9bac228f69f961; }, error: (null) Downloading iOS 18.4 Simulator (22E238): Error: Error Domain=SimDiskImageErrorDomain Code=5 "(-67061 invalid signature (code or signature have been modified)" UserInfo={NSLocalizedDescription=(-67061 invalid signature (code or signature have been modified), unusableErrorDetail=} When trying to install in Xcode I get the following error message: Any idea on how to get this fixed is appreciated!

I am missing device support for IOS 18.5 in xcode. I tried installing xcode 16.4, xcode 16.4 beta and xcode 26 beta 2 but none of them generated folder for 18.5. Is this happening only for me or everyone. Please provide me 18.5 folder if anyone has it. I would appreciate a lot.

Submitted feedback FB17075016 Xcode 16.3 release macOS 15.4 iOS 18.4 / iPadOS 18.4 release builds Memory graph fails to build when targeting physical devices running release builds referenced above. Memory graph will build against a simulator device.

https://developer.apple.com/documentation/xcodekit/creating_a_source_editor_extension I created new MacOS project and added a Xcode Source Editor Extension target to the project. I run the extension in debug mode with extension target, but the extension is not show up in Editor menu debug mode Xcode. Xcode version is 15.3(released) MacOS version is 14.4.1 Sonoma

I’m blocked debugging a watchOS app on a physical Apple Watch. The iPhone connects to Xcode normally (wired), but the Watch either fails to connect with a tunnel timeout or disappears entirely from Xcode after I unpaired it inside Devices & Simulators. Environment Mac: macOS 26.x (Apple Silicon Mac) Xcode: 26.2 iPhone: iOS 26.1 Apple Watch Ultra: watchOS 26.2 (build 23S303) Connection: iPhone connected to Mac via USB (trusted). Watch paired to iPhone and working normally in the Watch app. Issue A (when Watch is visible in Xcode) In Xcode → Window → Devices and Simulators, the Watch shows up but is not usable and fails to connect. Error: “Previous preparation error: A connection to this device could not be established.” “Timed out while attempting to establish tunnel using negotiated network parameters.” In some attempts the Watch shows “Capacity: Unknown” / limited details, and then fails during preparation. Issue B (after unpairing Watch in Xcode only) I unpaired/removed the Watch in Xcode (Devices & Simulators). I did not unpair the Watch from the iPhone. Now: iPhone appears in Xcode and works normally for builds. Watch is still paired to the iPhone and works normally. Watch no longer appears anywhere in Xcode Devices & Simulators (no paired watch section, no watch run destination). What I’ve tried Reboots of Mac, iPhone, Watch (multiple times) Watch unlocked, awake; iPhone unlocked and close to Watch Verified Watch is paired and connected in iPhone Watch app Developer Mode enabled on iPhone and Watch Wi-Fi and Bluetooth ON (Mac/iPhone/Watch), tried toggling both Tried on home Wi-Fi and also with iPhone hotspot (same result) Resetting trust prompts / reconnecting iPhone via USB, re-trusting Mac Apple Watch: “Clear Trusted Computers” Xcode: removing/re-adding devices; clearing derived data; restarting Xcode Watch Developer networking test: Responsiveness = Medium (430 RPM) Questions 1. Is this a known issue/regression with Xcode 26.2 + watchOS 26.2 tunneling (CoreDevice / devicectl)? 2. Is there an Apple-supported way to force Xcode to re-discover a paired Watch after it was removed from Xcode Devices & Simulators (without unpairing the Watch from the iPhone)? 3. Any recommended logs or diagnostic steps I should collect (Console logs, sysdiagnose, specific Xcode/CoreDevice logs) to include in a Feedback report? If helpful, I can provide the full error text from Xcode’s Devices window and any logs you recommend. Thank you in advance,

Hello Apple Developer Community, I'm experiencing an issue with file download functionality in the iOS Simulator after updating to Xcode 26 RC (Build 17A321). Issue Description: When attempting to download files in the iOS Simulator via Safari, the download prompt appears correctly, but after tapping the 'Download' button, files are not being saved to the Files app. The download appears to do nothing with no error message, no indication of failure, but the file simply doesn't appear in Downloads or anywhere in the Files app. Environment: Xcode Version: 26.0 RC (17A321) iOS Simulator Version: 26.0 RC (23A339) Device Simulated: iPhone Air Steps to Reproduce: Open Safari in the iOS Simulator Navigate to a downloadable file (PDF, ZIP, etc.) Tap to initiate download Download prompt appears as expected Tap the 'Download' button Check the Files app → Downloads folder (empty) Expected Behavior: Files should download normally as they do on physical devices and as they did in previous Xcode versions. Actual Behavior: The download prompt dismisses after tapping 'Download', but no file appears in the Files app. No error message is shown, and there's no indication that the download failed, it simply appears as if nothing happened. Additional Information: Downloads work correctly on physical device (iOS 26 RC 23A340) This functionality worked properly in previous Xcode versions I have created a bug report to Feedback assistant: FB20190927 Thanks in advance for any assistance.

I just downloaded Xcode26, and am trying to download the new simulator to be able to run and test my app. But the downloads folder just shows that it's stuck on "Fetching download information ..." even 15 minutes after it started. I tried restarting Xcode but didn't help. Internet connection is good. Any tips to get it working?

Ever since updating to Xcode 16.3, auto-completing variable names in lldb does not work. Is this a known bug? Is there a workaround to get it do auto-complete again?

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

dSYM size became thrice for builds generated via xcode 26 compared to xcode 16. These are all release builds.

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!

hy! apple developer community! No, I have a problem that's driving me crazy: Multiple commands produce '/Users/giulia/Library/Developer/Xcode/DerivedData/ScheduledStudy-dcmmhcdncitvfkdditbjoipfalqg/Build/Products/Debug-iphonesimulator/singintestwidgetExtension.appex/Info.plist'. Can you help me fix it? I know it's probably stupid, but I've been trying to fix it for days. There aren't two info.plist file, and that's why I don't quite understand. If you could help me, you'd be doing me a favor. Thanks for your time. P.S. I'm sorry, but I'm just starting out with programming and I'm also quite young.

We use several UIKit and AVFoundation APIs in our project, including: setAlternateIconName(_:completionHandler:) getAllTasks(completionHandler:) loadMediaSelectionGroup(for:completionHandler:) Moreover, we use the Swift Concurrency versions for these APIs: @MainActor func setAlternateIconName(_ alternateIconName: String?) async throws var allTasks: [URLSessionTask] { get async } func loadMediaSelectionGroup(for mediaCharacteristic: AVMediaCharacteristic) async throws -> AVMediaSelectionGroup? Everything worked well with these APIs in Xcode 16.2 and earlier, but starting from Xcode 16.3 (and in 16.4), they cause crashes. We've rewritten the APIs to use completion blocks instead of async/await, and this approach works. Stack traces: setAlternateIconName(_:completionHandler:) var allTasks: [URLSessionTask] { get async } loadMediaSelectionGroup(for:completionHandler:) Also, I attached some screenshots from Xcode 16.4.