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Getting a basic URL Filter to work
I haven’t been able to get this to work at any level! I’m running into multiple issues, any light shed on any of these would be nice: I can’t implement a bloom filter that produces the same output as can be found in the SimpleURLFilter sample project, after following the textual description of it that’s available in the documentation. No clue what my implementation is doing wrong, and because of the nature of hashing, there is no way to know. Specifically: The web is full of implementations of FNV-1a and MurmurHash3, and they all produce different hashes for the same input. Can we get the proper hashes for some sample strings, so we know which is the “correct” one? Similarly, different implementations use different encodings for the strings to hash. Which should we use here? The formulas for numberOfBits and numberOfHashes give Doubles and assign them to Ints. It seems we should do this conversing by rounding them, is this correct? Can we get a sample correct value for the combined hash, so we can verify our implementations against it? Or ignoring all of the above, can we have the actual code instead of a textual description of it? 😓 I managed to get Settings to register my first attempt at this extension in beta 1. Now, in beta 2, any other project (including the sample code) will redirect to Settings, show the Allow/Deny message box, I tap Allow, and then nothing happens. This must be a bug, right? Whenever I try to enable the only extension that Settings accepted (by setting its isEnabled to true), its status goes to .stopped and the error is, of course, .unknown. How do I debug this? While the extension is .stopped, ALL URL LOADS are blocked on the device. Is this to be expected? (shouldFailClosed is set to false) Is there any way to manually reload the bloom filter? My app ships blocklist updates with background push, so it would be wasteful to fetch the filter at a fixed interval. If so, can we opt out of the periodic fetch altogether? I initially believed the API to be near useless because I didn’t know of its “fuzzy matching” capabilities, which I’ve discovered by accident in a forum post. It’d be nice if those were documented somewhere! Thanks!!
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2.8k
Jul ’25
how can i pass the passkeyRegistration back to the user agent(web)
After registe Passkey with webauthn library, i create a passkeyRegistration with follow, let passkeyRegistration = ASPasskeyRegistrationCredential(relyingParty: serviceIdentifier, clientDataHash: clientDataHashSign, credentialID: credentialId, attestationObject: attestationObject) and then completeRegistrationRequest like that, extensionContext.completeRegistrationRequest(using: passkeyRegistration) But a bad outcome occurred from user agent. NotAllowedError:The request is not allowed by the user agent or the platform in the current context. And the return data rawID & credentialPublicKey is empty,
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513
Jul ’25
iOS 26: keyboardLayoutGuide does not give the correct constraint
In iOS 26, keyboardLayoutGuide does not provide the correct constraint when using third-party input method. A demo’s source code is attached to FB18594298 to illustrate the issue. The setup includes: An inputAccessoryView above keyboard An input box anchored to the top of the inputAccessoryView using the following constraint: [self.view.keyboardLayoutGuide.topAnchor constraintEqualToAnchor:self.inputBoxContainerView.bottomAnchor] Expected Behavior: Before iOS 26, when keyboard toggled by clicking the input box, the input box should move above the inputAccessoryView. Actual Behavior: However, on iOS 26, when switching to a third-party IME (e.g. 百度输入法baidu,搜狗输入法sogou,微信输入法wechat), then click the input box, the input box is above the keyboard instead of the inputAccessoryView, and is covered by the inputAccessoryView.
Topic: UI Frameworks SubTopic: UIKit Tags:
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421
Jul ’25
交易无法结束 (Transactions Unable to Finish)
有一个用户反馈7月8日充值了3笔后一直无法发起新的购买,总是提示已经购买。我们查了是之前的交易无法结束,我们使用StoreKit2,已经调用await transaction.finish()成功结束交易了,但是每次发起新支付时,Transaction.unfinished还会返回之前已完成的交易信息。 是设备或AppleID的问题么?用户尝试了重启设备、重新登录AppleID都没用。有什么办法解决呢? 用户无法结束的苹果交易id为:200002703899379、200002703900716、200002703902023。 A user reported that after making 3 purchases on July 8th, they have been unable to initiate new purchases, always receiving a prompt that the item has already been purchased. Upon investigation, we found that the previous transactions couldn't be finalized. We use StoreKit2 and have successfully called await transaction.finish() to end the transactions. However, every time a new payment is initiated, Transaction.unfinished still returns information about the previously completed transactions. Could this be an issue with the device or Apple ID? The user has tried restarting the device and re-logging into their Apple ID, but these attempts were unsuccessful. Is there any way to resolve this? The Apple transaction IDs that the user is unable to finalize are: 200002703899379, 200002703900716, 200002703902023.
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1.3k
Jul ’25
Local Network permission appears to be ignored after reboot, even though it was granted
We have a Java application built for macOS. On the first launch, the application prompts the user to allow local network access. We've correctly added the NSLocalNetworkUsageDescription key to the Info.plist, and the provided description appears in the system prompt. After the user grants permission, the application can successfully connect to a local server using its hostname. However, the issue arises after the system is rebooted. When the application is launched again, macOS does not prompt for local network access a second time—which is expected, as the permission was already granted. Despite this, the application is unable to connect to the local server. It appears the previously granted permission is being ignored after a reboot. A temporary workaround is to manually toggle the Local Network permission off and back on via System Settings > Privacy & Security, which restores connectivity—until the next reboot. This behavior is highly disruptive, both for us and for a significant number of our users. We can reproduce this on multiple systems... The issues started from macOS Sequoia 15.0 By opening the application bundle using "Show Package Contents," we can launch the application via "JavaAppLauncher" without any issues. Once started, the application is able to connect to our server over the local network. This seems to bypass the granted permissions? "JavaAppLauncher" is also been used in our Info.plist file
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Jul ’25
iOS 26 lets you swipe to delete history
Hello. I’m on iOS 26. I’m very protective over my children’s phone and use screen time religiously. ios 26 does have delete history grayed out , but there’s a glitch! You’re able to swipe and delete history under the bookmarks history and tabs section. Also if you type in a website like Walmart, it will bring it up and then allow you to swipe to the left and hit the red delete history and it shows up nowhere in your history! please help me find a fix for this!! i do allow safari but definitely want to be able to check the websites being viewed!!! also - iOS 26 does not let u block apple.comunder your not allowed websites. Which means they can now use Apple Maps and third party browser on Apple.com for example under the simple weather app before I had Apple blocked to where none of this could be accessed through stock apple apps! i appreciate any help!!!
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Jul ’25
Inability to Communicate via APDU on iOS Despite NFC Tag Detection
Background: We are developing a cross-platform mobile application that communicates with a custom NFC-enabled hardware device. The hardware expects ISO7816-style APDU commands for data exchange and functions correctly with Android using the IsoDep protocol. Observed Issue on iOS: On iOS, the tag is only detectable via NFCNdefReaderSession, which provides access to INFCNdefTag. Attempting to use NFCTagReaderSession with NFCPollingOption.Iso14443 (which is required for APDU communication) results in no tag detection. As a result, the tag is inaccessible for APDU-based communication on iOS. Since NFCNdefReaderSession does not support APDU, we are unable to establish the required command channel. Constraints: The hardware firmware cannot be changed to support NDEF-based command interpretation. The device expects raw ISO-DEP APDU commands (i.e., Class-Instruction-Param1-Param2-Data-Le). Impact: The lack of ISO7816 tag detection on iOS prevents the app from sending APDU commands, resulting in a platform-specific feature limitation. Functionality that relies on secure, structured APDU communication is unavailable to iOS users, even though it works seamlessly on Android.
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Jul ’25
CoreMediaError with Lightning HDMI output on FairPlay content
Hello, our application is unable to HDMI output FairPlay protected content to TV via official Lightning HDMI AV Adapter, by checking the console log on mediaplayerd it is found that a CoreMediaErrorDomain Code=-19156 is raised, but we are unable to know what this error code means. default 11:18:15.121584+0800 mediaplaybackd keyboss ckb_customURLReadCallback: 0x7fa62f800 60/0 customURLReqID 4 isComplete 1 err -19156 error <private> (0) dokeyCallbacksExist 0 default 11:18:15.121670+0800 mediaplaybackd keyboss ckb_processErrorForRequest: 0x7fa62f800 60/0 handler 4 err 0 default 11:18:15.121752+0800 mediaplaybackd <<<< FigCustomURLHandling >>>> curll_cancelRequestOnQueue: 0x7fa031360: requestID: 4 default 11:18:15.121932+0800 mediaplaybackd keyboss ckb_transitionRequestToTerminalState: 0x7fa62f800 60/0 reqFin err Error Domain=CoreMediaErrorDomain Code=-19156 (-19156) dokeyCallbacksExist 0 default 11:18:15.122025+0800 mediaplaybackd keyboss ckb_transitionRequestToTerminalState: 0x7fa62f800 60/0 retry default 11:18:15.123195+0800 mediaplaybackd <<<< FigCPECryptorPKD >>>> PostKeyRequestErrorOccurred: 0x7fab7be80 029592C2-093D-400D-B57F-7AB06CC292D1 key request error: Error Domain=CoreMediaErrorDomain Code=-19160 (-19160)
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Jul ’25
Insight into BaseBoard/FrontBoardServices Crashes Needed
We're seeing a sharp uptick in BaseBoard/FrontBoardServices crashes since we migrated from UIApplicationDelegate to UIWindowSceneDelegate. Having exhausted everything on my end short of reverse engineering BaseBoard or making changes without being able to know if they work, I need help. I think all I need to get unstuck is an answer to these questions, if possible: What does -[BSSettings initWithSettings:] enumerate over? If I know what's being enumerated, I'll know what to look for in our app. What triggers FrontBoardServices to do this update? If I can reproduce the crash--or at least better understand when it may happen--I will be better able to fix it Here's two similar stack traces: App_(iOS)-crashreport-07-30-2025_1040-0600-redacted.crash App_(iOS)-crashreport-07-30-2025_1045-0600-redacted.crash Since these are private trameworks, there is no documentation or information on their behavior that I can find. There are other forum posts regarding this crash, on here and on other sites. However, I did not find any that shed any insight on the cause or conditions of the crash. Additionally, this is on iPhone, not macOS, and not iPad. This post is different, because I'm asking specific questions that can be answered by someone with familiarity on how these internal frameworks work. I'm not asking for help debugging my application, though I'd gladly take any suggestions/tips! Here's the long version, in case anyone finds it useful: In our application, we have seen a sharp rise in crashes in BaseBoard and FrontBoardServices, which are internal iOS frameworks, since we migrated our app to use UIWindowSceneDelegate. We were using exclusively UIApplicationDelegate before. The stack traces haven't proven very useful yet, because we haven't been able to reproduce the crashes ourselves. Upon searching online, we have learned that Baseboard/Frontsoardservices are probably copying scene settings upon something in the scene changing. Based on our crash reports, we know that most of our users are on an iPhone, not an iPad or macOS, so we can rule out split screen or window resizing. Our app is locked to portrait as well, so we can also rule out orientation changes. And considering the stack trace is in the middle of an objc_retain_x2 call, which is itself inside of a collection enumeration, we are assuming that whatever is being enumerated probably was changed or deallocated during enumeration. Sometimes it's objc_retain_x2, and sometimes it's a release call. And sometimes it's a completely different stack trace, but still within BaseBoard/FrontBoardServices. I suspect these all share the same cause. Because it's thread 0 that crashed, we know that BaseBoard/FrontBoardServices were running on the main thread, which means that for this crash to occur, something might be changing on a background thread. This is what leads me to suspect a race condition. There are many places in our app where we accidentally update the UI from a background thread. We've fixed many of them, but I'm sure there are more. Our app is large. Because of this, I think background UI are the most likely cause. However, since I can't reproduce the crash, and because none of our stack traces clearly show UI updates happening on another thread at the same time, I am not certain. And here's the stack trace inline, in case the attachments expire or search engines can't read them: Thread 0 name: Thread 0 Crashed: objc_retain_x2 (libobjc.A.dylib) BSIntegerMapEnumerateWithBlock (BaseBoard) -[BSSettings initWithSettings:] (BaseBoard) -[BSKeyedSettings initWithSettings:] (BaseBoard) -[FBSSettings _settings:] (FrontBoardServices) -[FBSSettings _settings] (FrontBoardServices) -[FBSSettingsDiff applyToMutableSettings:] (FrontBoardServices) -[FBSSettingsDiff settingsByApplyingToMutableCopyOfSettings:] (FrontBoardServices) -[FBSSceneSettingsDiff settingsByApplyingToMutableCopyOfSettings:] (FrontBoardServices) -[FBSScene updater:didUpdateSettings:withDiff:transitionContext:completion:] (FrontBoardServices) __94-[FBSWorkspaceScenesClient _queue_updateScene:withSettings:diff:transitionContext:completion:]_block_invoke_2 (FrontBoardServices) -[FBSWorkspace _calloutQueue_executeCalloutFromSource:withBlock:] (FrontBoardServices) __94-[FBSWorkspaceScenesClient _queue_updateScene:withSettings:diff:transitionContext:completion:]_block_invoke.cold.1 (FrontBoardServices) __94-[FBSWorkspaceScenesClient _queue_updateScene:withSettings:diff:transitionContext:completion:]_block_invoke (FrontBoardServices) _dispatch_client_callout (libdispatch.dylib) _dispatch_block_invoke_direct (libdispatch.dylib) __FBSSERIALQUEUE_IS_CALLING_OUT_TO_A_BLOCK__ (FrontBoardServices) -[FBSMainRunLoopSerialQueue _targetQueue_performNextIfPossible] (FrontBoardServices) -[FBSMainRunLoopSerialQueue _performNextFromRunLoopSource] (FrontBoardServices) __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ (CoreFoundation) __CFRunLoopDoSource0 (CoreFoundation) __CFRunLoopDoSources0 (CoreFoundation) __CFRunLoopRun (CoreFoundation) CFRunLoopRunSpecific (CoreFoundation) GSEventRunModal (GraphicsServices) -[UIApplication _run] (UIKitCore) UIApplicationMain (UIKitCore) (null) (UIKitCore) main (AppDelegate.swift:0) 0x1ab8cbf08 + 0
Topic: UI Frameworks SubTopic: General Tags:
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Jul ’25
New push notifications for widgets seem too limited for actual production-level apps
I was very excited to see the addition of push notifications for widgets. However upon further inspection, the way it is implemented seems too limiting for real life apps. I have an app for time tracking with my own backend. The app syncs with my backend in the main executable (main target). My widgets are more lightweight as they only access data in the shared app container, but they don't perform sync with the server directly to avoid race conditions with the main app. I was under the impression that the general direction of the platform is to be doing most things in the main app target (also App Intents work that way for the most part), so the fact that the WidgetPushHandler just calls the widget's method to reload the timeline is very unfortunate. In an ideal scenario I also need the main app to be 'woken up' to perform the sync with the server, and once that's done I'd update the widget's timeline and where I would just read data from the shared app container. So, my questions are: What is the recommended way of updating the widgets when this push notification arrives in the case that the main app target needs to perform the sync first? Is there any way how to detect that the method func timeline(for configuration: InteractiveTrackingWidgetConfigurationAppIntent, in context: Context) was called as a result of the push notification being received? Can I somehow schedule a background task from the widget's reloadTimeline() function? How can I get the push token later, in case that I don't save it right away the first time the WidgetPushHandler's pushTokenDidChange() is called? Thank you for your work on this and hopefully for your answers. FB19356256
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256
Aug ’25
MKReverseGeocodingRequest and CNPostalAddress from MKMapItem
My app is currently using CLGeocoder to get a CLPlacemark, then using placemark.postalAddress with CNPostalAddressFormatter to get an attributed string for the full address, I then enumerate its attributes to pull out specific elements like just the street or state or zip etc. This is deprecated in iOS 26 with MKReverseGeocodingRequest being the intended replacement. This API returns an MKMapItem which doesn’t provide a CNPostalAddress - you can get a full address as a String but not structured address data that I’m seeing. Am I missing some way to get the postal address? Or is it a non-goal to provide that anymore? Thanks!
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483
Aug ’25
Request for Device Temperature Monitoring and Thermal Attribution Analysis APIs
Background: During daily usage of iOS devices, devices experience noticeable thermal issues. This heating not only affects user experience, but may also lead to device performance throttling, shortened battery life, and other problems. We need better understanding and monitoring of device thermal states to optimize application performance and user experience. Issues Encountered: Insufficient thermal monitoring capabilities: Unable to obtain real-time accurate temperature data from devices Difficult power consumption analysis: Hard to determine which specific modules or threads cause high power consumption and heating Requested Solutions: Temperature Monitoring API: Provide accessible device temperature reading interfaces Thermal Attribution Analysis Capability: During heating events, we expect to receive more detailed power consumption monitoring data, such as CPU, GPU, network, location services, display, high power consumption thread stacks and other information to help developers identify high energy consumption operations
3
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303
Aug ’25
Popover in Toolbar Causes Crash in Catalyst App on macOS 26
Hi everyone, I’ve encountered an issue where using a popover inside the toolbar of a Catalyst app causes a crash on macOS 26 beta 5 with Xcode 26 beta 5. Here’s a simplified code snippet: import SwiftUI struct ContentView: View { @State private var isPresentingPopover = false var body: some View { NavigationStack { VStack { } .padding() .toolbar { ToolbarItem { Button(action: { isPresentingPopover.toggle() }) { Image(systemName: "bubble") } .popover(isPresented: $isPresentingPopover) { Text("Hello") .font(.largeTitle) .padding() } } } } } } Steps to reproduce: Create a new iOS app using Xcode 26 beta 5. Enable Mac Catalyst (Match iPad). Add the above code to show a Popover from a toolbar button. Run the app on macOS 26, then click the toolbar button. The app crashes immediately upon clicking the toolbar button. Has anyone else run into this? Any workarounds or suggestions would be appreciated! Thanks!
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256
Aug ’25
Unable to Remove “Sign in with Apple” of my app
Hello, I’m trying to remove the “Sign in with Apple” for my app via the iOS settings (also tried on a Mac, and on the web via account.apple.com). When I tap “Stop Using”, nothing happens, the dialog disappear but the app remains listed. Someone said on a forum that the issue is linked with the ServiceId that doesn't exist anymore. But how to recover it ? And anyway this behavior is unintended and creates a gap in the process. Has anyone experienced this before? Is there a known fix, or should I contact Apple Support directly for server-side revocation? Thank you!
2
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761
Aug ’25
Core ML model decryption on Intel chips
About the Core ML model encryption mention in:https://developer.apple.com/documentation/coreml/encrypting-a-model-in-your-app When I encrypted the model, if the machine is M chip, the model will load perfectly. One the other hand, when I test the executable on an Intel chip macbook, there will be an error: Error Domain=com.apple.CoreML Code=9 "Operation not supported on this platform." UserInfo={NSLocalizedDescription=Operation not supported on this platform.} Intel test machine is 2019 macbook air with CPU: Intel i5-8210Y, OS: 14.7.6 23H626, With Apple T2 Security Chip. The encrypted model do load on M2 and M4 macbook air. If the model is NOT encrypted, it will also load on the Intel test machine. I did not find in Core ML document that suggest if the encryption/decryption support Intel chips. May I check if the decryption indeed does NOT support Intel chip?
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364
Aug ’25
Source view disappearing when interrupting a zoom navigation transition
When I use the .zoom transition in a navigation stack, I get a glitch when interrupting the animation by swiping back before it completes. When doing this, the source view disappears. I can still tap it to trigger the navigation again, but its not visible on screen. This seems to be a regression in iOS 26, as it works as expected when testing on iOS 18. Has someone else seen this issue and found a workaround? Is it possible to disable interrupting the transition? Filed a feedback on the issue FB19601591 Screen recording: https://share.icloud.com/photos/04cio3fEcbR6u64PAgxuS2CLQ Example code @State var showDetail = false @Namespace var namespace var body: some View { NavigationStack { ScrollView { showDetailButton } .navigationTitle("Title") .navigationBarTitleDisplayMode(.inline) .navigationDestination(isPresented: $showDetail) { Text("Detail") .navigationTransition(.zoom(sourceID: "zoom", in: namespace)) } } } var showDetailButton: some View { Button { showDetail = true } label: { Text("Show detail") .padding() .background(.green) .matchedTransitionSource(id: "zoom", in: namespace) } } }
Topic: UI Frameworks SubTopic: SwiftUI
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1.5k
Aug ’25
Manipulation stops working when changing rooms
This post documents an issue I reported in feedback FB19610114 and see if anyone knows of a workaround. Here is a copy of the feedback. Short version Manipulation (SwiftUI OR RealityKit) fails to translate entities after changing rooms. By changing rooms, I mean a human wearing an Apple Vision Pro leaving one room and entering another room. Once this issue occurs, it impacts all apps that use these features. A device restart is the only solution I have to fix it. Feedback FB19610114 This is an odd one. I'm using the new Manipulation Component in visionOS 26. Most of the time this works well. Sometime it stops working and when it does the only way to get it working again is to reboot the headset. When this happens, I can continue to rotate and scale items, but translation no longer works. It is as if the item is stuck to a fixed point in the parent scene (window, volume, etc). When this bug occurs, it affects every app across the entire operating system that is using manipulation, including the RealityKit component AND the SwiftUI version. This is not limited to one app and is not limited to apps that I am working on. Once this error occurs, it affects literally any application across the operating system that is using this API, including apps from Apple. I won't speculate on the cause of this, but I do know of one way where I can always get it to happen. Here is how to reproduce it: Make an Xcode project with a single entity that uses the Manipulation Component. There is no need to customize the configuration of this component. The default implementation will work. Build and run this app on device. You can keep running from device or quit and launch the app like normal on device. Open the app and manipulate the entity - it should work as expected. Physically walk into another room. It is vital that you leave the current room that you are in and enter a different room entirely. Use the digital crown to recenter your view and bring your window or volume to you. Test the manipulation on the entity again - it should still be working as expected at this point. Physically, move yourself and your headset into the original room where you started. Use the digital crown to recenter your view and bring your window or volume to you. Test the manipulation on the entity again - you should now see the issue. When I follow the steps above, then 100% of the time manipulation translation stops working at this point. It will impact any application using this API. The only way to fix it is to restart my headset. A few points to keep in mind It does not matter if an app is actively being run from Xcode. When this occurs, it impacts every single app, not just one. When this occurs, rotation and scaling continue to work, but the entity/view cannot be translated. This impacts BOTH the SwiftUI version and the RealityKit version. When this occurs, the only way to "fix" it is to reboot the device.
6
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945
Aug ’25
Safari 18+ network bug - randomly - The network connection was lost
We are experiencing an issue with Safari in all versions from 18.0 to 18.5 that does not occur in version 17. It affects both iPhones and Macs. And does not happen in Chrome or Windows. The problem is impacting our customers, and our monitoring tools show a dramatic increase in error volume as more users buy/upgrade to iOS 18. The issue relates to network connectivity that is lost randomly. I can reliably reproduce the issue online in production, as well as on my local development environment. For example our website backoffice has a ping, that has a frequency of X seconds, or when user is doing actions like add to a cart increasing the quantity that requires backend validation with some specific frequency the issue is noticable... To test this I ran a JS code to simulate a ping with a timer that calls a local-dev API (a probe that waits 2s to simulate "work") and delay the next HTTP requests with a dynamic value to simulate network conditions: Note: To even make the issue more clear, I'm using GET with application/json payload to make the request not simple, and require a Pre-flight request, which doubles the issue. (async () =&amp;gt; { for (let i = 0; i &amp;lt; 30; i++) { try { console.log(`Request start ${i} ${new Date().toLocaleString()}`); const res = await fetch(`https://api.redated.com:8090/1/*****/probe?`, { method: 'GET', mode: "cors", //headers: {'Content-Type': 'text/plain'}, headers: { 'Content-Type': 'application/json' }, }); console.log(`Request end ${i} ${new Date().toLocaleString()} status:`, res.status); } catch (err) { console.error(`Request ${i} ${new Date().toLocaleString()} error:`, err); } let delta = Math.floor(Math.random() * 10); console.log("wait delta",delta); await new Promise(r =&amp;gt; setTimeout(r, 1000 - delta)); } })(); For simplicity lets see a case where it fails 1 time only out of 10 requests. (Adjusting the "delta" var on the time interval create more or less errors...) This are the results: The network connection was lost error, which is false, since this is on my localhost machine, but this happens many times and is very reproducible in local and production online. The dev-tools and network tab shows empty for status error, ip, connection_id etc.. its like the request is being terminated very soon. Later I did a detailed debugging with safari and wireshark to really nail down the network flow of the problem: I will explain what this means: Frame 10824 – 18:52:03.939197: new connection initiated (SYN, ACK, ECE). Frame 10831 – 18:52:04.061531: Client sends payload (preflight request) to the server. Frame 10959 – 18:52:09.207686: Server responds with data to (preflight response) to the client. Frame 10960 – 18:52:09.207856: Client acknowledges (ACK) receipt of the preflight response. Frame 10961 – 18:52:09.212188: Client sends the actual request payload after preflight OK and then server replies with ACK. Frame 11092 – 18:52:14.332951: Server sends the final payload (main request response) to the client. Frame 11093 – 18:52:14.333093: captures the client acknowledging the final server response, which marks the successful completion of the main request. Frame 11146 – 18:52:15.348433: [IMPORTANT] the client attempts to send another new request just one second later, which is extremely close to the keep-alive timeout of 1 second. The last message from the server was at 18:52:14.332951, meaning the connection’s keep-alive timeout is predicted to end around 18:52:15.332951 but it does not. The new request is sent at 18:52:15.348433, just microseconds after the predicted timeout. The request leaves before the client browser knows the connection is closed, but by the time it arrives at the server, the connection is already dead. Frame 11147 – 18:52:15.356910: Shows the server finally sending the FIN,ACK to indicate the connection is closed. This happens slightly later than the predicted time, at microsecond 356910 compared to the expected 332951. The FIN,ACK corresponds to sequence 1193 from the ACK of the last data packet in frame 11093. Conclusions: The root cause is related to network handling issues, when the server runs in a setting of keep-alive behavior and keep-alive timeout (in this case 1s) and network timming issue with Safari reusing a closed connection without retrying. In this situation the browser should retry the request, which is what other browsers do and what Safari did before version 18, since it did not suffer from this issue. This behaviour must differ from previous Safari versions (however i read all the public change logs and could not related the regression change). Also is more pronounced with HTTP/1.1 connections due to how the keep-alive is handled. When the server is configured with a short keep-alive timeout of 1 second, and requests are sent at roughly one-second intervals, such as API pings at fixed intervals or user actions like incrementing a cart quantity that trigger backend calls where the probability of failure is high. This effect is even more apparent when the request uses a preflight with POST because it doubles the chance, although GET requests are also affected. This was a just a test case, but in real production our monitoring tools started to detect a big increment with this network error at scale, many requests per day... which is very disrupting, because user actions are randomly being dropped when the user actions and timming happens to be just near a previous connection, where keep alive timeout kicks-in, but because the browser is not yet notified it re-uses the same connection, but by the time it arrived the server is a dead connection. The safari just does nothing about it, does not even retry, be it a pre-flight or not, it just gives this error. Other browsers don't have this issue. Thanks!
10
4
1.7k
Aug ’25