General: Forums subtopic: App & System Services > Networking TN3151 Choosing the right networking API Networking Overview document — Despite the fact that this is in the archive, this is still really useful. TLS for App Developers forums post Choosing a Network Debugging Tool documentation WWDC 2019 Session 712 Advances in Networking, Part 1 — This explains the concept of constrained networking, which is Apple’s preferred solution to questions like How do I check whether I’m on Wi-Fi? TN3135 Low-level networking on watchOS TN3179 Understanding local network privacy Adapt to changing network conditions tech talk Understanding Also-Ran Connections forums post Extra-ordinary Networking forums post Foundation networking: Forums tags: Foundation, CFNetwork URL Loading System documentation — NSURLSession, or URLSession in Swift, is the recommended API for HTTP[S] on Apple platforms. Moving to Fewer, Larger Transfers forums post Testing Background Session Code forums post Network framework: Forums tag: Network Network framework documentation — Network framework is the recommended API for TCP, UDP, and QUIC on Apple platforms. Building a custom peer-to-peer protocol sample code (aka TicTacToe) Implementing netcat with Network Framework sample code (aka nwcat) Configuring a Wi-Fi accessory to join a network sample code Moving from Multipeer Connectivity to Network Framework forums post NWEndpoint History and Advice forums post Network Extension (including Wi-Fi on iOS): See Network Extension Resources Wi-Fi Fundamentals TN3111 iOS Wi-Fi API overview Wi-Fi Aware framework documentation Wi-Fi on macOS: Forums tag: Core WLAN Core WLAN framework documentation Wi-Fi Fundamentals Secure networking: Forums tags: Security Apple Platform Security support document Preventing Insecure Network Connections documentation — This is all about App Transport Security (ATS). WWDC 2017 Session 701 Your Apps and Evolving Network Security Standards [1] — This is generally interesting, but the section starting at 17:40 is, AFAIK, the best information from Apple about how certificate revocation works on modern systems. Available trusted root certificates for Apple operating systems support article Requirements for trusted certificates in iOS 13 and macOS 10.15 support article About upcoming limits on trusted certificates support article Apple’s Certificate Transparency policy support article What’s new for enterprise in iOS 18 support article — This discusses new key usage requirements. Technote 2232 HTTPS Server Trust Evaluation Technote 2326 Creating Certificates for TLS Testing QA1948 HTTPS and Test Servers Miscellaneous: More network-related forums tags: 5G, QUIC, Bonjour On FTP forums post Using the Multicast Networking Additional Capability forums post Investigating Network Latency Problems forums post WirelessInsights framework documentation iOS Network Signal Strength forums post Share and Enjoy — Quinn “The Eskimo!” @ Developer Technical Support @ Apple let myEmail = "eskimo" + "1" + "@" + "apple.com" [1] This video is no longer available from Apple, but the URL should help you locate other sources of this info.

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The scenario is, in a macOS app (primarly), main thread needs to wait for some time for a certain 'event'. When that event occurs, the main thread is signaled, it gets unblocked and moves on. An example is, during shutdown, a special thread known as shutdown thread waits for all other worker threads to return (thread join operation). When all threads have returned, the shutdown thread signals the main thread, which was waiting on a timer, to continue with the shutdown flow. If shutdown thread signals the main thread before the later's timer expires, it means all threads have returned. If main thread's timer expires first, it means some threads have failed to join (probably stuck in infinite loop due to bug, disk I/O etc.). This post is to understand how main thread can wait for some time for the shutdown thread. There are two ways: a) dispatch_semaphore_t b) pthread conditional variable (pthread_cond_t) and mutex (pthread_mutex_t). Expanding a bit on option (b) using conditional variable and mutex: // This method is invoked on the main thread bool ConditionSignal::TimedWait() noexcept { struct timespec ts; pthread_mutex_t * mutex = (pthread_mutex_t *) (&vPosix.vMutexStorage[0]); pthread_cond_t * cond = (pthread_cond_t *) (&vPosix.vCondVarStorage[0]); // Set the timer to 3 sec. clock_gettime(CLOCK_REALTIME, &ts); ts.tv_sec += 3; pthread_mutex_lock(mutex); LOG("Main thread has acquired the mutex and is waiting!"); int wait_result = pthread_cond_timedwait(cond, mutex, &ts); switch (wait_result) { case 0: LOG("Main thread signaled!"); return true; case ETIMEDOUT: LOG("Main thread's timer expired!"); return false; default: LOG("Error: Unexpected return value from pthread_cond_timedwait: " + std::to_string(wait_result)); break; } return false; } // This method is invoked on shutdown thread after all worker threads have returned. void ConditionSignal::Raise() noexcept { pthread_mutex_t * mutex = (pthread_mutex_t *) (&vPosix.vMutexStorage); pthread_cond_t * cond = (pthread_cond_t *) (&vPosix.vCondVarStorage); pthread_mutex_lock(mutex); LOG("[Shutdown thread]: Signalling main thread..."); pthread_cond_signal(cond); pthread_mutex_unlock(mutex); } Both options allow the main thread to wait for some time (for shutdown thread) and continue execution. However, when using dispatch_semaphore_t, I get the following warning: Thread Performance Checker: Thread running at User-interactive quality-of-service class waiting on a lower QoS thread running at Default quality-of-service class. Investigate ways to avoid priority inversions Whereas, with conditional variables, there are no warnings. I understand the warning - holding the main thread can prevent it from responding to user events, thus causing the app to freeze. And in iOS, the process is killed if main thread takes more than 5 secs to return from applicationWillTerminate(_:) delegate method. But in this scenario, the main thread is on a timed-wait, for some milliseconds i.e., it is guaranteed to not get blocked indefinitely. While this is described for macOS, this functionality is required for all Apple OSes. What is the recommend way?

Hello, I need help with iCloud Activation Lock on my device. Device: iPhone 16 Pro 256GB Serial Number: HCJD73C0MJ IMEI: 350766435041555 / 350766435124831 I cannot access the original Apple ID, so the device is stuck on Activation Lock. I am the legitimate owner and I have proof of purchase and ID for verification. Please advise on the proper steps to resolve this issue. Thank you.

macOS 26 "Tahoe" is allocating much more memory for apps than former macOS versions: A customer contacted me with my app's Thumbnail extension allocating so much memory that her 48 GB RAM Mac Mini ran into "out of application memory" state. I couldn't identify any memory leak in my extension's code nor reproduce the issue, but found the main app allocating as much as 5 times the memory compared to running on macOS 15 or lower. This productive app is explicitly using "Liquid Glass" views as well as implicitly e.g. for an inspector pane. So I created a sample app, just based on Xcode's template of a document-based app, and the issue is still showing (although less dramatically): This sample app allocates 22 MB according to Tahoe's Activity Monitor, while Sequoia only requires 16 MB: macOS 15.6.1 macOS 26.2 Is anyone experiencing similar issues? I suspect some massive leak in Tahoe's memory management, and just filed a corresponding feedback (FB21967167).

Hey, I am just about to prepare my app for Swift 6, and facing the issue that UserDefaults is not Sendable. The documentation states that its thread safe, so I am wondering, why is it not marked as Sendable? Was it just forgotten? Is it safe to mark it as nonisolated(unsafe) or @unchecked Sendable?

I'll try to ask a question that makes sense this time :) . I'm using the following method on NSFileManager: (BOOL) getRelationship:(NSURLRelationship *) outRelationship ofDirectoryAtURL:(NSURL *) directoryURL toItemAtURL:(NSURL *) otherURL error:(NSError * *) error; Sets 'outRelationship' to NSURLRelationshipContains if the directory at 'directoryURL' directly or indirectly contains the item at 'otherURL', meaning 'directoryURL' is found while enumerating parent URLs starting from 'otherURL'. Sets 'outRelationship' to NSURLRelationshipSame if 'directoryURL' and 'otherURL' locate the same item, meaning they have the same NSURLFileResourceIdentifierKey value. If 'directoryURL' is not a directory, or does not contain 'otherURL' and they do not locate the same file, then sets 'outRelationship' to NSURLRelationshipOther. If an error occurs, returns NO and sets 'error'. So this method falsely returns NSURLRelationshipSame for different directories. One is empty, one is not. Really weird behavior. Two file path urls pointing to two different file paths have the same NSURLFileResourceIdentifierKey? Could it be related to https://developer.apple.com/forums/thread/813641 ? One url in the check lived at the same file path as the other url at one time (but no longer does). No symlinks or anything going on. Just plain directory urls. And YES calling -removeCachedResourceValueForKey: with NSURLFileResourceIdentifierKey causes proper result of NSURLRelationshipOther to be returned. And I'm doing the check on a background queue.

Hello. We are facing very silent and hardly replicable issue. All UserDefaults.standard data the application saved and was using to determine the state of app is lost and app behaves as if it was freshly installed. The issue always occurs only if we leave app on background for long time or if we manually swipe the app from the background apps. In case we swipe, this issue can occur in minutes, hours or up to 2 days by our latest testing. One important factor is that the app was developed using iOS18 in which issue never occured. Next it was being tested on iOS26 and it did everytime. Any currently available version of iOS26 reported this issue, all the way up to 26.2.1 (23C71). Our application is going through major upgrade of its whole lifecycle and services so it is possible this issue is caused by a bug in development as the production version does not report this issue neither on iOS26 of any version. The following list contains how we tried to fix this issue but none of which helped. App prewarming in the background (postpone all initialization including searching UserDefaults.standard for when isProtectedDataAvailable) Calling UserDefaults.standard.synchronize() everytime after saving data despite it is not recomended Built app using different SDK's (tested on iOS18 and iOS26 SDK) Distributed the app from local machine aswell as on TestFlight itself We searched through currently opened and closed issues for third-party libraries app uses regarding 'iOS26' and 'UserDefaults', especially those who were added recently with no success. The structure using which we save data into UserDefaults.standard did not change, we have only added few more settings to save through the lifecycle of the app after update. We estimate the overall increase is merely 30% more of what it used to be in previous version. Any ideas are much appreciated. We are considering to use different or fully custom ways to store app's settings.

I'm importing SwiftUI, Foundation and Charts into an iOS app I'm writing in Swift in Xcode Playgrounds and am getting this error: error: Couldn't look up symbols: protocol witness table for Foundation.Date : Charts.Plottable in Charts the code looks like this in just two example files: file 1, the view import Foundation import SwiftUI import Charts import PlaygroundSupport struct FirstChart_WithDates: View { private let data = ChartDateAndDoubleModel.mockData(months: 3) var body: some View { Chart(data) { item in BarMark( x: .value("Label", item.date, unit: .month), y: .value("Value", item.value) ) } .padding() .aspectRatio(1, contentMode: .fit) .dynamicTypeSize(.accessibility1) ChartDateAndDoubleModelView(data: data) } } struct ChartDateAndDoubleModelView: View { var data: [ChartDateAndDoubleModel] var body: some View { VStack { HeaderRowView(texts: ["date", "value"]) ForEach(data) { datum in HStack { Text(datum.date.formatted(date: .abbreviated, time: .omitted)) .frame(maxWidth: .infinity) // TODO: Format for 2 decimal places. Text(datum.value, format: .number.precision(.fractionLength(2))) .frame(maxWidth: .infinity) } } } .padding(.bottom, 8) .overlay(.quaternary, in: .rect(cornerRadius: 8).stroke()) .padding() } } struct HeaderRowView: View { var texts: [String] var body: some View { HStack(spacing: 2.0) { ForEach(texts, id: \.self) { text in Text(text) .padding(4) .frame(maxWidth: .infinity) .background(.quaternary) } } .font(.headline) .mask(UnevenRoundedRectangle(topLeadingRadius: 8, topTrailingRadius: 8)) } } and file 2, the model: import Foundation import SwiftUI import Charts // ChartDateAndDoubleModel.swift // // // Created by Michael Isbell on 2/10/26. // public struct ChartDateAndDoubleModel: Identifiable { public let id = UUID() public let date: Date public let value: Double } public extension ChartDateAndDoubleModel { static func mockData(months: Int = 5) -> [ChartDateAndDoubleModel] { var data: [ChartDateAndDoubleModel] = [] let calendar = Calendar(identifier: .gregorian) let currentDate = Date() for month in 0..<months { //add month to current date and append to data data.append( ChartDateAndDoubleModel( date: calendar.date(byAdding: .month, value: month, to: currentDate)!, value: Double.random(in: 0...1000) ) ) } return data } }

I am building an app for iOS and MacCatalyst that indexes files by storing their local paths. Because the app relies on the file remaining at its original location, I only want to accept items that can be opened in place. I am struggling to determine if an item is "Open In Place" compatible early in the drag-and-drop lifecycle. Specifically: In dropInteraction(_:canHandle:) and dropInteraction(_:sessionDidUpdate:), calling itemProvider.registeredTypeIdentifiers(fileOptions: [.openInPlace]) returns an empty array. Only once the drop is actually committed in dropInteraction(_:performDrop:) does that same call return the expected type identifiers. This creates a poor user experience. I want to validate the "In Place" capability at the very start of the session so the drop target only activates for valid files. If an item is ephemeral (like a dragged photo from the Photos app or a temporary export), the drop zone should not react at all. How can I reliably detect if an NSItemProvider supports .openInPlace before the performDrop delegate method is called?

A user of my app reported that when my app copies files from a QNAP NAS to a folder on their Mac, they get the error "Result too large". When copying the same files from the Desktop, it works. I asked them to reproduce the issue with the sample code below and they confirmed that it reproduces. They contacted QNAP for support who in turn contacted me saying that they are not sure they can do anything about it, and asking if Apple can help. Both the app user and QNAP are willing to help, but at this point I'm also unsure how to proceed. Can someone at Apple say anything about this? Is this something QNAP should solve, or is this a bug in macOS? P.S.: I've had users in the past who reported the same issue with other brands, mostly Synology. import Cocoa @main class AppDelegate: NSObject, NSApplicationDelegate { func applicationDidFinishLaunching(_ aNotification: Notification) { let openPanel = NSOpenPanel() openPanel.canChooseDirectories = true openPanel.runModal() let source = openPanel.urls[0] openPanel.canChooseFiles = false openPanel.runModal() let destination = openPanel.urls[0] do { try copyFile(from: source, to: destination.appendingPathComponent(source.lastPathComponent, isDirectory: false)) } catch { NSAlert(error: error).runModal() } NSApp.terminate(nil) } private func copyFile(from source: URL, to destination: URL) throws { if try source.resourceValues(forKeys: [.isDirectoryKey]).isDirectory == true { try FileManager.default.createDirectory(at: destination, withIntermediateDirectories: false) for source in try FileManager.default.contentsOfDirectory(at: source, includingPropertiesForKeys: nil) { try copyFile(from: source, to: destination.appendingPathComponent(source.lastPathComponent, isDirectory: false)) } } else { try copyRegularFile(from: source, to: destination) } } private func copyRegularFile(from source: URL, to destination: URL) throws { let state = copyfile_state_alloc() defer { copyfile_state_free(state) } var bsize = UInt32(16_777_216) if copyfile_state_set(state, UInt32(COPYFILE_STATE_BSIZE), &bsize) != 0 { throw NSError(domain: NSPOSIXErrorDomain, code: Int(errno)) } else if copyfile_state_set(state, UInt32(COPYFILE_STATE_STATUS_CB), unsafeBitCast(copyfileCallback, to: UnsafeRawPointer.self)) != 0 { throw NSError(domain: NSPOSIXErrorDomain, code: Int(errno)) } else if copyfile(source.path, destination.path, state, copyfile_flags_t(COPYFILE_DATA | COPYFILE_SECURITY | COPYFILE_NOFOLLOW | COPYFILE_EXCL | COPYFILE_XATTR)) != 0 { throw NSError(domain: NSPOSIXErrorDomain, code: Int(errno)) } } private let copyfileCallback: copyfile_callback_t = { what, stage, state, src, dst, ctx in if what == COPYFILE_COPY_DATA { if stage == COPYFILE_ERR { return COPYFILE_QUIT } } return COPYFILE_CONTINUE } }

I am developing an iOS/iPadOS application and have encountered some behavior regarding Files App and security-scoped bookmarks that I would like to clarify. Additionally, I would like to report some behavior which might include a potential issue. Question1: Accessing deleted files via bookmark (Specification clarification) Our app saves file URLs as bookmarks, which file that user has selected on Files App or app-created so to open a file which user has modified previously in the next launch. When a user deletes a file in Files App (moves a file to Recently Deleted), the app can still resolve the bookmark and access the file for read/write operations. Is this behavior intended? In other words, is it correct that a bookmark can access a file that has been deleted in Files App but not permanently removed? Question2: Overwriting a file in Recently Deleted (Potential bug) We noticed that overwriting a file in Recently Deleted behaves differently depending on the method used. Current implementation 1.Create a temporary file in the same directory 2.Write content to the temporary file 3.Delete the original file ([NSFileManager removeItemAtURL:error:]) 4.Move the temporary file to the original file path ([NSFileManager moveItemAtURL:toURL:error:]) Result: The file disappears from Files App Recently Deleted. In contrast, using [NSFileManager replaceItemAtURL:withItemAtURL:] keeps the file visible in Recently Deleted. Is this difference designed behavior? If not, this may be a bug. Question3: Detecting files in Recently Deleted We want to detect whether a file resides in Recently Deleted, but we cannot find a reliable and officially supported method. Recently Deleted files appear under .Trash, but using the path alone is not a reliable method. We have tried the following APIs without success: [NSURL getResourceValue:forKey:NSURLIsHiddenKey error:] [NSURL checkResourceIsReachableAndReturnError:] [NSFileManager fileExistsAtPath:] [NSFileManager isReadableFileAtPath:] [NSFileManager getRelationship:ofDirectory:NSTrashDirectory inDomain:NSUserDomainMask toItemAtURL:error:] We could not obtain the Recently Deleted folder URL using standard APIs. [NSFileManager URLsForDirectory:NSTrashDirectory inDomains:NSUserDomainMask] [NSFileManager URLForDirectory:NSTrashDirectory inDomain:NSUserDomainMask appropriateForURL:url create:error:] Could you advise a safe and supported way to detect Recently Deleted files properly by the app?

Hello, I have a .app NSApplication which is ran as a LaunchDaemon, in it's lifecycle I never call any AppKit functions (I start it with CFRunLoopRun). (mentioned on this post as well). I intercept a couple of signals using signal(s) in order to trigger CFRunLoopStop(CFRunLoopGetCurrent()) to do some cleanup. This LaunchDaemon has the purpose of providing VPN connectivity, as such I call connect functions that trigger the "Add VPN configuration" dialog (I can't provide extra details about this, as I integrate another SDK so I'm not sure what happens under the hood) and I noticed that whenever it is displayed, after allowing it, during the lifecycle of the application when it's time to send the signal, the signal isn't received. I tried re-adding the NSApp callbacks in order to investigate, but it looks like those aren't called as well. I'm interested in knowing more about this scenario and what happens... I couldn't really find information about this dialog... Thanks!

Environment: Xcode 26 iOS 26 Also tested on iOS 18 (working correctly) Description: I'm experiencing a behavior change with URL(fileURLWithPath:) when the filename starts with a tilde (~) character. On iOS 18, passing a filename like ~MyFile.txt to URL(fileURLWithPath:) treats the tilde as a literal character. However, on iOS 26, the same code resolves the tilde as the home directory, resulting in unexpected output. Minimal Example: let filename = "~MyFile.txt" let url = URL(fileURLWithPath: filename) print(url.lastPathComponent) Expected Result (iOS 18): ~MyFile.txt Actual Result (iOS 26): 924AF0C4-C3CD-417A-9D5F-733FBB8FCF29 The tilde is being resolved to the app's container directory, and lastPathComponent returns the container UUID instead of the filename. Questions: 1. Is this an intentional behavior change in iOS 26? 2. Is there documentation about this change? 3. What is the recommended approach for extracting filename components when the filename may contain special characters like ~? Workaround: Using NSString.lastPathComponent works correctly on both iOS versions: let filename = "~MyFile.txt" let result = (filename as NSString).lastPathComponent // Returns: "~MyFile.txt" ✅ Is this the recommended approach going forward?

I've implemented func urlSession(_ session: URLSession, task: URLSessionTask, willPerformHTTPRedirection response: HTTPURLResponse, newRequest request: URLRequest, completionHandler: @escaping (URLRequest?) -> Void) and func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didWriteData bytesWritten: Int64, totalBytesWritten: Int64, totalBytesExpectedToWrite: Int64) I've put a breakpoint in each but the BP in willPerformHTTPRedirection never fires. When the didWriteData fires and I inspect downloadTask.originalRequest I see my original request URL When I inspect downloadTask.currentRequest the returned request contains a different URL. I'm the farthest thing from an HTTP wizard, but I had thought when originalRequest differs from currentRequest there had been some sort of server-side 'redirection'. Is there a way for my code to receive a callback when something like this happens? NOTE: my download code works fine, I'm just hoping to detect the case when currentRequest changes. any/all guidance greatly appreciated on the off chance it helps, are are my original and current request values: (lldb) po downloadTask.originalRequest ▿ Optional<URLRequest> ▿ some : https://audio.listennotes.com/e/p/c524803c1a90412f922948274ecc3625/ (lldb) po downloadTask.currentRequest ▿ Optional<URLRequest> ▿ some : https://26973.mc.tritondigital.com:443/OMNY_HAPPIERWITHGRETCHENRUBIN_PODCAST_P/media-session/76cfceb2-1801-4570-b830-ded57611a9cf/d/clips/796469f9-ea34-46a2-8776-ad0f015d6beb/e1b22d0b-6974-4bb8-81ba-b2480119983c/2f35a8ca-b982-44e9-8122-b3dc000ae0e1/audio/direct/t1769587393/Ep_571_Want_to_Join_Us_for_a_No-Spend_February_Plus_a_Better_Word_for_Squats.mp3?t=1769587393&in_playlist=751ada7f-ded3-44b9-bfb8-b2480119985b&utm_source=Podcast

In a class, I call the following (edited to simplify, but it matches the real case). If I do this: func getData() -> someClass? { _ = someURL.startAccessingSecurityScopedResource() if let data = NSData(contentsOf: someURL as URL) { do { let unarchiver = try NSKeyedUnarchiver(forReadingFrom: data as Data) print((unarchiver.decodeObject(of: [NSArray.self, someClass.self /* and few others*/], forKey: oneKey) as? someClass)?.aProperty) if let result = unarchiver.decodeObject(of: [NSArray.self, someClass.self /* same other types*/], forKey: oneKey) as? someClass { unarchiver.finishDecoding() print("unarchived success") return result } else { unarchiver.finishDecoding() print("unarchiving failed") return someClass() } } catch { return nil } } I get a failure on log : unarchiving failed But if I comment out the print(unarchiver.decodeObject) - line 8, it works and I get unarchived success // print((unarchiver.decodeObject(of: [NSArray.self, someClass.self /* and few others*/], forKey: oneKey) as? someClass)?.aProperty) However, when I do exactly the same for another class (I've compared line by line to be sure), it works even with the print statement. What could be happening here ?

The documentation says: The caching behavior of the NSURL and CFURL APIs differ. For NSURL, all cached values (not temporary values) are automatically removed after each pass through the run loop. You only need to call the removeCachedResourceValueForKey: method when you want to clear the cache within a single execution of the run loop. The CFURL functions, on the other hand, do not automatically clear cached resource values. The client has complete control over the cache lifetimes, and you must use CFURLClearResourcePropertyCacheForKey or CFURLClearResourcePropertyCache to clear cached resource values. https://developer.apple.com/documentation/foundation/nsurl/removeallcachedresourcevalues()?language=objc Is this really true? In my experience I've had to explicitly remove cached resource values via -removeAllCachedResourceValues or removeCachedResourceValueForKey: otherwise the URL contains stale values. For example on a URL that no longer exists I attempted to read NSURLIsHiddenKey and the last value was already cached. Instead of getting a NSFileNoSuchFileError I get the old cache value unless explicitly call -removeCachedResourceValueForKey: first and I'm fairly certain the value was cached on a previous run loop churn.

I'm a font developer. In the development process, I will revise a font and overwrite the OTF file that is currently enabled (registered) with macOS. If I then launch an app, it will immediately use the revised version of the font; while apps that are already loaded will continue to use the old version. This suggests that each app is loading new and separate font data, rather than getting it from some existing cache in memory. Yet macOS does have a "font cache" of some sort. Some apps, like TextEdit, seem to only load the fonts that they need to use. However, other apps, like Pages, load every enabled (registered) font on the OS!! (According to the Open Files list in Activity Monitor.) Given that /System/Library/Fonts/ is 625 Mb, and we can't disable any of it, isn't that a lot of data to be repeating? How many fonts is too many fonts? I can't find much documentation about the process.

I decode an object with NSKeyedArchiver (SecureCoding): typealias BoolArray = Array<Array<Bool>> let val = decoder.decodeObject(of: NSArray.self, forKey: someKey) as? BoolArray I get the following log: *** -[NSKeyedUnarchiver validateAllowedClass:forKey:] allowed unarchiving safe plist type ''NSNumber' (0x204cdbeb8) [/System/Library/Frameworks/Foundation.framework]' for key 'NS.objects', even though it was not explicitly included in the client allowed classes set: '{( "'NSArray' (0x204cd5598) [/System/Library/Frameworks/CoreFoundation.framework]" )}'. This will be disallowed in the future. I changed by adding NSNumber.self in the list : let val = decoder.decodeObject(of: [NSArray.self, NSNumber.self], forKey: someKey) as? BoolArray No more warning in log. Is there a reason for this ?

I get several warnings in log: *** -[NSKeyedUnarchiver validateAllowedClass:forKey:] allowed unarchiving safe plist type ''NSNumber' (0x204cdbeb8) [/System/Library/Frameworks/Foundation.framework]' for key 'NS.objects', even though it was not explicitly included in the client allowed classes set: '{( "'NSArray' (0x204cd5598) [/System/Library/Frameworks/CoreFoundation.framework]" )}'. This will be disallowed in the future. I am not sure how to understand it: I have removed every NSNumber.self in the allowed lists for decode. To no avail, still get the avalanche of warnings. What is the key NS.objects about ? What may allowed classes set: '{( "'NSArray' be referring to ? An inclusion of NSArray.self in a list for decode ? The type of a property in a class ?