The app becomes unresponsive when pushing a new page. The screen is covered by the _UIParallaxOverlayView class, blocking all gestures. Are there any scenarios where the transition animation might suddenly stop mid-process? Or could you provide more information to help me troubleshoot this issue? I noticed: When the issue occurs, the FromViewController is displayed on the screen. The ToViewController also exists in the view tree, but it's not visible on the screen. _UIParallaxOverlayView only appears on iOS 18 and above. The animation appears to be controlled by +[UIView _fluidParallaxTransitionsEnabledWithTraitCollection:], which is _os_feature_enabled_impl("UIKit", "fluid_parallax_transitions"). Reference

I’m experiencing a crash in WKWebView on iOS 26 Developer Beta 5 and Beta 6 with the following exception: CALayer position contains NaN: [nan 65] The crash occurs when the following CSS properties are applied to content displayed in WKWebView: -webkit-user-select: none; -webkit-touch-callout: none; This issue happens consistently whenever these styles are set, leading to the crash inside WKWebView. Is this a known bug in the current iOS 26 betas, or is there a recommended workaround?

Environment • Device: iOS 26 Developer Beta 5 (23A5308g) • Xcode: 16.3 Short description The app crashes the moment the user tries to long-press to select text inside a WKWebView, double-tap an image with Text (magnifier appears) The exception is CALayer position contains NaN. frame = (nan,0;0,48) chorPoint=(inf, 0) and it is thrown in the UI process. Build & run any project that hosts a WKWebView. Inject the following CSS via script (this is what we do to suppress the native callout menu): WKWebView *webView = [[WKWebView alloc] initWithFrame:self.view.bounds configuration:[WKWebViewConfiguration new]]; NSString *js = @"document.documentElement.style.webkitUserSelect='none';" "document.documentElement.style.webkitTouchCallout='none';"; [webView evaluateJavaScript:js completionHandler:nil]; [self.view addSubview:webView]; Incident Identifier: EE6FB046-5087-4F15-A72D-A74965347A30 CrashReporter Key: 29e8e58e02a07557adb4ce3f463d764f3ce8bbd5 Hardware Model: iPhone16,1 Process: wallet [642] Path: /private/var/containers/Bundle/Application/4B4E609A-C8BF-4C56-AB2A-1638249B98A5/wallet.app/wallet Identifier: xxxx Version: xxxx AppStoreTools: 16F7 AppVariant: 1:iPhone16,1:18 Code Type: ARM-64 (Native) Role: Foreground Parent Process: launchd [1] Coalition: xxxxx Date/Time: 2025-08-06 12:05:24.0732 +0800 Launch Time: 2025-08-06 11:49:40.3802 +0800 OS Version: iPhone OS 26.0 (23A5308g) Release Type: Beta Baseband Version: 3.02.02 Report Version: 104 Exception Type: EXC_CRASH (SIGABRT) Exception Codes: 0x0000000000000000, 0x0000000000000000 Termination Reason: SIGNAL 6 Abort trap: 6 Terminating Process: wallet [642] Triggered by Thread: 0 Application Specific Information: abort() called Last Exception Backtrace: 0 CoreFoundation 0x185e058c8 __exceptionPreprocess + 164 1 libobjc.A.dylib 0x182d797c4 objc_exception_throw + 88 2 CoreFoundation 0x185e908d4 -[NSException initWithCoder:] + 0 3 QuartzCore 0x18678a874 CA::Layer::set_position(CA::Vec2<double> const&, bool) + 160 4 QuartzCore 0x1869a7270 -[CALayer setPosition:] + 52 5 UIKitCore 0x18c4ac564 -[UIView _backing_setPosition:] + 176 6 UIKitCore 0x18cefdf0c -[UIView setCenter:] + 220 7 UIKitCore 0x18cd9f794 -[_UIEditMenuContentPresentation _displayPreparedMenu:titleView:reason:didDismissMenu:configuration:] + 936 8 UIKitCore 0x18cd9f3c0 __54-[_UIEditMenuContentPresentation _displayMenu:reason:]_block_invoke + 104 9 UIKitCore 0x18ced1060 -[UIEditMenuInteraction _editMenuPresentation:preparedMenuForDisplay:completion:] + 384 10 UIKitCore 0x18cd9f2e4 -[_UIEditMenuContentPresentation _displayMenu:reason:] + 304 11 UIKitCore 0x18cd9f0d8 -[_UIEditMenuContentPresentation displayMenu:configuration:] + 64 12 UIKitCore 0x18ced0344 __58-[UIEditMenuInteraction presentEditMenuWithConfiguration:]_block_invoke + 260 13 UIKitCore 0x18ced1f8c __80-[UIEditMenuInteraction _prepareMenuAtLocation:configuration:completionHandler:]_block_invoke + 80 14 UIKitCore 0x18cc8403c __109-[UITextContextMenuInteraction _editMenuInteraction:menuForConfiguration:suggestedActions:completionHandler:]_block_invoke + 180 15 UIKitCore 0x18cc84584 __107-[UITextContextMenuInteraction _querySelectionCommandsForConfiguration:suggestedActions:completionHandler:]_block_invoke + 148 16 WebKit 0x1a05ae5d4 WTF::CompletionHandler<void (WebKit::DocumentEditingContext&&)>::operator()(WebKit::DocumentEditingContext&&) + 64 17 WebKit 0x1a05bb468 WTF::Detail::CallableWrapper<WTF::CompletionHandler<void (IPC::Connection*, IPC::Decoder*)> IPC::Connection::makeAsyncReplyCompletionHandler<Messages::WebPage::RequestDocumentEditingContext, WTF::CompletionHandler<void (WebKit::DocumentEditingContext&&)>>(WTF::CompletionHandler<void (WebKit::DocumentEditingContext&&)>&&, WTF::ThreadLikeAssertion)::'lambda'(IPC::Connection*, IPC::Decoder*), void, IPC::Connection*, IPC::Decoder*>::call(IPC::Connection*, IPC::Decoder*) + 196 18 WebKit 0x19fcf5db8 WTF::Detail::CallableWrapper<WebKit::AuxiliaryProcessProxy::sendMessage(WTF::UniqueRef<IPC::Encoder>&&, WTF::OptionSet<IPC::SendOption>, std::__1::optional<IPC::ConnectionAsyncReplyHandler>, WebKit::AuxiliaryProcessProxy::ShouldStartProcessThrottlerActivity)::$_1, void, IPC::Connection*, IPC::Decoder*>::call(IPC::Connection*, IPC::Decoder*) + 64 19 WebKit 0x19fce54f0 IPC::Connection::dispatchMessage(WTF::UniqueRef<IPC::Decoder>) + 340 20 WebKit 0x19fcf5aa0 IPC::Connection::dispatchIncomingMessages() + 536 21 JavaScriptCore 0x19a8f85d4 WTF::RunLoop::performWork() + 552 22 JavaScriptCore 0x19a8f838c WTF::RunLoop::performWork(void*) + 36 23 CoreFoundation 0x185da6230 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 28 24 CoreFoundation 0x185da61a4 __CFRunLoopDoSource0 + 172 25 CoreFoundation 0x185d83c6c __CFRunLoopDoSources0 + 232 26 CoreFoundation 0x185d598b0 __CFRunLoopRun + 820 27 CoreFoundation 0x185d58c44 _CFRunLoopRunSpecificWithOptions + 532 28 GraphicsServices 0x224ce0498 GSEventRunModal + 120 29 UIKitCore 0x18b6c84b8 -[UIApplication _run] + 792 30 UIKitCore 0x18b66cbc0 UIApplicationMain + 336 31 wallet 0x1046f8558 0x1046f4000 + 17752 32 dyld 0x182dcdb18 start + 6332

I am using Apple's original Lightning Digital AV-adapter (Lightning-to-HDMI dongle) to connect my iPhone to an external display via a HDMI cable. I need to synchronize rendering with the external display's refresh rate, so I create a new CADisplayLink tied to the external display's UIScreen: UIScreen.screens[externalDisplayIdx].displayLink(withTarget:, selector:). The callback is being called regularly, but with increasing delay relative to the CADisplayLink.timestamp, so the next time the callback is called, I have less and less time to draw the next frame (see the snippet below). Assuming 60 FPS, the value of secondsTillDeadline starts at an arbitrary value in the range of approx -0.0001 to 0.0166667, and then it slowly decreases towards zero (and for a brief period it goes into small negative numbers). Once it reaches zero, it flips back to 0.0166667 and continues to decrease again. This cycle repeats indefinitely. Changing the external display's resolution (UIScreen's mode) or the CADisplayLink's preferredFrameRateRange to a lower FPS does not seem to have any effect on the temporal drifting (even the rate of change seem to be the same). When I create a new CADisplayLink for the iPhone's main screen, the value of secondsTillDeadline is stable, it does not drift and it is very close to 0.0166667, as expected. Is this drift caused by the external monitor or by Apple's Lightning-to-HDMI dongle ...or is the problem somewhere else? Can the drifting be stopped? func onDisplayLinkUpdate(displayLink: CADisplayLink) { // Gradually decreases from 0.01667 to -0.0001, then flips back to 0.01667 and continues to decrease let secondsTillDeadline = displayLink.targetTimestamp - CACurrentMediaTime() }

Hi all, After upgrading to the iOS 26 beta, the scrolling in my SwiftUI chat view is completely broken. The exact same code works perfectly on iOS 18. Context: I have a chat view using ScrollViewReader and a vertically-reversed ScrollView (with .rotationEffect(.degrees(180))). Each message row (MessageBubble) uses multiple simultaneousGesture handlers: Horizontal drag for swipe-to-reply (and other actions: pin, delete) Long press for showing popover/actions Vertical scroll for normal chat scrolling This was working great on iOS 18. In iOS 26 beta, the vertical scroll is either completely disabled, jittery, or hijacked by the message row’s drag gestures, even though .simultaneousGesture is used (see code below). Minimal Repro Sample MessageListView.swift swift Copy Edit ScrollViewReader { proxy in ScrollView(.vertical, showsIndicators: false) { LazyVStack(spacing: 0) { // ... grouped messages ForEach(...) { ... MessageBubble(...) // see below } Color.clear.frame(height: 8).id("BOTTOM_ANCHOR") } .padding(.horizontal, 4) .rotationEffect(.degrees(180)) } .rotationEffect(.degrees(180)) } MessageBubble.swift struct MessageBubble: View { // ... var body: some View { // horizontal swipe-to-reply gesture let dragGesture = DragGesture(minimumDistance: 10) // ... ZStack { // ... HStack { ... } // ... .simultaneousGesture( DragGesture(minimumDistance: 0) // for long press // ... ) .simultaneousGesture(dragGesture) // for horizontal swipe } // ... } }

Unexpected SwiftUI Transaction Behavior This minimal example demonstrates an unexpected behavior in SwiftUI's Transaction API: var transaction = Transaction(animation: .none) transaction.addAnimationCompletion { print("This should not be called!") } The Issue The completion handler is called immediately after creation, even though the transaction was never used in any SwiftUI animation context (like withTransaction or other animation-related APIs). Expected vs Actual Behavior Expected: The completion handler should only be called after the transaction is actually used in a SwiftUI animation. Actual: The completion handler is called right after creation, regardless of whether the transaction is used or not. Current Workaround To avoid this, I'm forced to implement defensive programming: only creating transactions with completion handlers at the exact moment they're going to be used. This adds unnecessary complexity and goes against the intuitive usage of the Transactions API.

My setup: a UILabel with text in it and then let aBugRenderer = UIGraphicsImageRenderer(size: aBugLabel.bounds.size) let aBugImage = aBugRenderer.image { context in aBugLabel.drawHierarchy(in: aBugLabel.bounds, afterScreenUpdates: true) } The layout and everything is correct, the image is correct, but I used my colors in the displayP3 color space to configure the source UILabel.textColor And unfortunately, the resulted image ends up being sRGB IEC61966-2.1 color space and the color appears way bleaker than when it's drawn natively. Question: how can I set up the renderer so that it draws the same color.

Hi everyone, I’m currently testing iOS 26 on my iPhone as part of the developer program. According to Apple’s documentation and demo materials, a new screenshot animation was introduced in this version. However, when I take a screenshot on my device, the animation remains the same as in previous iOS versions. I’ve double-checked that I’m running the correct build of iOS 26, and I haven’t found any settings that might enable or disable this feature. Is anyone else experiencing the same issue? Could this new animation be device-specific, region-limited, or require additional configuration? Any insight would be appreciated! Thanks in advance, Alonso Rivera

please fix!

iOS 26 added smoothness to CIRoundedRectangleGenerator, for use with CIFilter.roundedRectangleGenerator. What should the smoothness value be to achieve the same corner curve as CALayerCornerCurve.continuous? Does it need to be calculated based on the extent size, if so, how?

I have filed a bug report for this (FB17734946), but I'm posting it here verbatim in case others have the same issue and in hopes of getting attention from an Apple engineer sooner. When calling setNeedsDisplayInRect on a CATiledLayer - or a UIView whose backing layer is CATiledLayer - one would expect to re-draw only a region identified by the rect passed to the method. This is even written in the documentation for the class: "Regions of the layer may be invalidated using the setNeedsDisplayInRect: method however the update will be asynchronous. While the next display update will most likely not contain the updated content, a future update will." However, upon calling this method, CATiledLayer redraws whole contents instead of just the tile at the specified rect, and it flashes when doing so. It behaves exactly the same as if one had called setNeedsDisplay without passing any rect; all contents are cleared and re-drawn again. I'm 100% sure I've passed in the correct rect of the exact tile that I need to redraw. I have even tried passing much smaller rects, but still the same. (And yes, the rect I've passed accounts for the current level of detail.) I have found this GitHub repo https://github.com/frankus/NetPhotoScroller, which based on discussion from here https://forums.macrumors.com/threads/catiledlayer-blanks-out-tiles-when-redrawing.1333948/ aims at solving these issues by using two private methods on CATiledLayer class: (void)setNeedsDisplayInRect:(CGRect)r levelOfDetail:(int)level; (BOOL)canDrawRect:(CGRect)rect levelOfDetail:(int)level; I have explored the repo in detail, however I wasn't able to test exactly this code from the GitHub repo. I have tried using those two private methods myself (through an Objective-C class that defines the methods in the header file and then a swift class which inherits it), but I couldn't solve the issue; the flashing and the full re-draw is still there. After doing a lot of research, the conclusion seems to be that one cannot use CATiledLayer with contents that are downloaded remotely, on demand, as tiles are being requested. I have, however, found one interesting thing which seems to work so far: before calling setNeedsDisplayInRect (or just setNeedsDisplay, as they behave the same for CATiledLayer in my testing), cache the current layer's contents, and after calling setNeedsDisplay (or setNeedsDisplayInRect), restore the contents back to the layer. This prevents flashing and preserves any tiles that were drawn at the time of the re-draw. let c = tiledLayer.contents tiledLayer.setNeedsDisplay(tileRect) tiledLayer.contents = c However! Docs clearly state the warning: Do not attempt to directly modify the contents property of a CATiledLayer object. Doing so disables the ability of a tiled layer to asynchronously provide tiled content, effectively turning the layer into a regular CALayer object. I believe this message implies modifying the contents property with some raw content, like image data, and that it may be safe to re-apply the existing contents (which are in my testing of type CAImageProvider) -- but I can't rely on an implementation detail in my production app. I have tested this and confirmed that the bug appears on: iPhone 14 Pro, iOS 18.5 iPhone 13 Pro, iOS 17.5.1 iPhone 5s, iOS 15.8.3 iPad Pro 1st gen, iPadOS 18.4.1 a couple simulator versions I can also confirm that the fix (to re-apply contents property) is also working properly on all these versions. Is this expected behavior, that tiled layer redraws itself entirely instead of redrawing specific tiles? Is it safe to modify contents of a CATiledLayer by re-applying the existing contents? If not, is there an alternative to avoid flashing?

We have a macOS app (not yet released, but in use by ourselves), that provides scoreboards for streaming sport events. Today it is expected, that there are nice animations for goals, etc. We are streaming using NDI, which requires a CVPixelBuffer for each frame. We currently create these animations using CABasicAnimation, CAAnimation and CAKeyframeAnimation. In addition we use ScreenCaptureKit to generate the frames. This works fine with 25/30 fps, as long as the window where our animations are performed in is visible. But this is not what it should be. We have a smaller window as main app window and control display performing the animations in reduced size, while the streaming animations need to be in HD format and later maybe in 4K. When using an offscreen window, the animations are not calculated. We get 1 frame per second or so. So we actually have to connect an external display to the MacBook and open the large windows there. Ugly solution. Do we use a completely wrong approach? Or is there a way to tell the macOS to perform the animations although it is an offscreen window? If it cannot work that way, what is an alternative?

Due to the release of ProMotion devices, the system may switch frame rates in certain scenarios, resulting in the loss of reference value for data collected through CADisplayLink callbacks at a fixed 60Hz frame rate. We cannot distinguish whether the slow callback of CADisplayLink is due to a stutter or a system switch in frame rate. I know Hitch Time Ratio, but I can't use this scheme for some reasons. How can I distinguish between stuck and frame rate gear shift in CADisplaylink callback? In iOS 15, CADisplayLink.preferredFrameRateRange.preferred always returns 0, while minimum and maximum do change. Can I use these minimum and maximum range values as criteria to distinguish between frame rate switching and stuttering?

Hi everyone, I'm encountering an intermittent crash on iOS 18 only (not reproducible locally, reported in Firebase Crashlytics) at transitionContext.completeTransition(!transitionContext.transitionWasCancelled) within my custom UIViewControllerAnimatedTransitioning. The same code runs fine on iOS 16 and 17 (no Crashlytics report for those iOS version) Here's the crash log: Crashed: com.apple.main-thread 0 libswiftCore.dylib 0x4391f0 swift_getObjectType + 40 1 ROOM 0x490c48 ItemDetailAnimator.navigationController(_:animationControllerFor:from:to:) + 47 (ItemDetailAnimator.swift:47) 2 ROOM 0x490f3c @objc ItemDetailAnimator.navigationController(_:animationControllerFor:from:to:) + 92 (<compiler-generated>:92) 3 UIKitCore 0xa2d7a4 -[UINavigationController _customTransitionController:] + 516 4 UIKitCore 0x2e51dc -[UINavigationController _immediatelyApplyViewControllers:transition:animated:operation:] + 2620 5 UIKitCore 0x1541d4 __94-[UINavigationController _applyViewControllers:transition:animated:operation:rescheduleBlock:]_block_invoke + 100 6 UIKitCore 0x150768 -[UINavigationController _applyViewControllers:transition:animated:operation:rescheduleBlock:] + 776 7 UIKitCore 0x2e7e44 -[UINavigationController pushViewController:transition:forceImmediate:] + 544 8 UIKitCore 0x2e4230 -[UINavigationController pushViewController:animated:] + 444 9 ROOM 0x66cb04 UINavigationController.pushViewController(_:animated:completion:) + 185 (UINavigationController+Room.swift:185) 10 ROOM 0x8cef4c ItemDetailCoordinator.start(animated:completion:) + 99 (ItemDetailCoordinator.swift:99) 11 ROOM 0xc6c95c protocol witness for Coordinator.start(animated:completion:) in conformance BaseCoordinator + 24 (<compiler-generated>:24) 12 ROOM 0x8ca520 AppCoordinator.startCoordinator(_:url:reference:animated:completion:) + 729 (AppCoordinator.swift:729) 13 ROOM 0x8cb248 protocol witness for URLSupportCoordinatorOpener.startCoordinator(_:url:reference:animated:completion:) in conformance AppCoordinator + 48 (<compiler-generated>:48) 14 ROOM 0xd6166c URLSupportCoordinatorOpener<>.open(url:openingController:reference:animated:completion:) + 118 (URLSupportedCoordinator.swift:118) 15 ROOM 0xc56038 RRAppDelegate.handleURL(url:completion:) + 588 (RRAppDelegate.swift:588) 16 ROOM 0xc502d0 RRAppDelegate.applicationDidBecomeActive(_:) + 330 (RRAppDelegate.swift:330) 17 ROOM 0xc5041c @objc RRAppDelegate.applicationDidBecomeActive(_:) + 52 (<compiler-generated>:52) 18 UIKitCore 0x1fb048 -[UIApplication _stopDeactivatingForReason:] + 1368 My animateTransition code is: ```func animateTransition( using transitionContext: UIViewControllerContextTransitioning) { guard let (fromView, toView, fromVC, toVC) = filterTargets(context: transitionContext) else { transitionContext.cancelInteractiveTransition() transitionContext.completeTransition(false) return } let containerView = transitionContext.containerView toView.frame = transitionContext.finalFrame(for: toVC) guard let targetView = fromVC.animationTargetView, let fromFrame = fromVC.animationTargetFrame, let toFrame = toVC.animationTargetFrame else { containerView.insertSubview(toView, aboveSubview: fromView) toView.frame = transitionContext.finalFrame(for: toVC) transitionContext.completeTransition(true) return } let newFromFrame = fromView.convert(fromFrame, to: containerView) let tempImageView: UIImageView if let target = targetView as? UIImageView, let image = targetImage ?? target.image, image.size.height != 0, target.frame.height != 0, image.size.width / image.size.height != target.frame.width / target.frame.height { targetImage = image tempImageView = UIImageView(image: image) tempImageView.frame = newFromFrame tempImageView.contentMode = .scaleAspectFit } else { tempImageView = targetView.room.asImageView() tempImageView.frame = newFromFrame } targetView.isHidden = true let tempFromView = containerView.room.asImageView() targetView.isHidden = false let tempHideView = UIView() containerView.addSubview(tempFromView) containerView.insertSubview(toView, aboveSubview: tempFromView) tempHideView.backgroundColor = .white toView.addSubview(tempHideView) containerView.addSubview(tempImageView) //Minus with item detail view y position //Need to minus navigation bar height of item detail view var tempHideViewFrame = toFrame tempHideViewFrame.origin.y -= toView.frame.origin.y tempHideView.frame = tempHideViewFrame let duration = transitionDuration(using: transitionContext) toView.alpha = 0 UIView.animate(withDuration: duration * 0.5, delay: duration * 0.5, options: .curveLinear, animations: { toView.alpha = 1 }) let scale: CGFloat = toFrame.width / newFromFrame.width let newFrame = CGRect( x: toFrame.minX - newFromFrame.minX * scale, y: toFrame.minY - newFromFrame.minY * scale, width: tempFromView.frame.size.width * scale, height: tempFromView.frame.size.height * scale) UIView.animate(withDuration: duration, delay: 0.0, options: [.curveEaseInOut], animations: { tempFromView.frame = newFrame tempImageView.frame = toFrame }, completion: { _ in tempHideView.removeFromSuperview() tempFromView.removeFromSuperview() tempImageView.removeFromSuperview() transitionContext.completeTransition(!transitionContext.transitionWasCancelled) }) }

One of our users reported a very strange bug where our app freezes and eventually crashes on some screen transitions. From different crash logs we could determine that the app freezes up when we call view.layoutIfNeeded() for animating constraint changes. It then gets killed by the watchdog 10 seconds later: Exception Type: EXC_CRASH (SIGKILL) Exception Codes: 0x0000000000000000, 0x0000000000000000 Termination Reason: FRONTBOARD 2343432205 <RBSTerminateContext| domain:10 code:0x8BADF00D explanation:scene-update watchdog transgression: app<bundleID(2A01F261-3554-44C0-B5A9-EBEB446484AD)>:6921 exhausted real (wall clock) time allowance of 10.00 seconds ProcessVisibility: Background ProcessState: Running WatchdogEvent: scene-update WatchdogVisibility: Background WatchdogCPUStatistics: ( "Elapsed total CPU time (seconds): 24.320 (user 18.860, system 5.460), 29% CPU", "Elapsed application CPU time (seconds): 10.630, 12% CPU" ) reportType:CrashLog maxTerminationResistance:Interactive> The crash stack trace looks slightly different, depending on the UI transition that is happening. Here are the two we observed so far. Both are triggered by the layoutIfNeeded() call. Thread 0 name: Dispatch queue: com.apple.main-thread Thread 0 Crashed: 0 CoreAutoLayout 0x1b09f90e4 -[NSISEngine valueForEngineVar:] + 8 1 UIKitCore 0x18f919478 -[_UIViewLayoutEngineRelativeAlignmentRectOriginCache origin] + 372 2 UIKitCore 0x18f918f18 -[UIView _nsis_center:bounds:inEngine:forLayoutGuide:] + 1372 3 UIKitCore 0x18f908e9c -[UIView(Geometry) _applyISEngineLayoutValuesToBoundsOnly:] + 248 4 UIKitCore 0x18f9089e0 -[UIView(Geometry) _resizeWithOldSuperviewSize:] + 148 5 CoreFoundation 0x18d0cd6a4 __NSARRAY_IS_CALLING_OUT_TO_A_BLOCK__ + 24 6 CoreFoundation 0x18d0cd584 -[__NSArrayM enumerateObjectsWithOptions:usingBlock:] + 432 7 UIKitCore 0x18f8e62b0 -[UIView(Geometry) resizeSubviewsWithOldSize:] + 128 8 UIKitCore 0x18f977194 -[UIView(AdditionalLayoutSupport) _is_layout] + 124 9 UIKitCore 0x18f976c2c -[UIView _updateConstraintsAsNecessaryAndApplyLayoutFromEngine] + 800 10 UIKitCore 0x18f903944 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 2728 11 QuartzCore 0x18ec15498 CA::Layer::layout_if_needed(CA::Transaction*) + 496 12 UIKitCore 0x18f940c10 -[UIView(Hierarchy) layoutBelowIfNeeded] + 312 Thread 0 name: Dispatch queue: com.apple.main-thread Thread 0 Crashed: 0 QuartzCore 0x18ec2cfe0 -[CALayer animationForKey:] + 176 1 UIKitCore 0x18fa5b258 UniqueAnimationKeyForLayer + 192 2 UIKitCore 0x18fa5ab7c __67-[_UIViewAdditiveAnimationAction runActionForKey:object:arguments:]_block_invoke_2 + 468 3 UIKitCore 0x18fa5ba5c -[_UIViewAdditiveAnimationAction runActionForKey:object:arguments:] + 1968 4 QuartzCore 0x18eb9e938 CA::Layer::set_bounds(CA::Rect const&, bool) + 428 5 QuartzCore 0x18eb9e760 -[CALayer setBounds:] + 132 6 UIKitCore 0x18f941770 -[UIView _backing_setBounds:] + 64 7 UIKitCore 0x18f940404 -[UIView(Geometry) setBounds:] + 340 8 UIKitCore 0x18f908f84 -[UIView(Geometry) _applyISEngineLayoutValuesToBoundsOnly:] + 480 9 UIKitCore 0x18f9089e0 -[UIView(Geometry) _resizeWithOldSuperviewSize:] + 148 10 CoreFoundation 0x18d0cd6a4 __NSARRAY_IS_CALLING_OUT_TO_A_BLOCK__ + 24 11 CoreFoundation 0x18d132488 -[__NSSingleObjectArrayI enumerateObjectsWithOptions:usingBlock:] + 92 12 UIKitCore 0x18f8e62b0 -[UIView(Geometry) resizeSubviewsWithOldSize:] + 128 13 UIKitCore 0x18f977194 -[UIView(AdditionalLayoutSupport) _is_layout] + 124 14 UIKitCore 0x18f976c2c -[UIView _updateConstraintsAsNecessaryAndApplyLayoutFromEngine] + 800 15 UIKitCore 0x18f916258 -[UIView(Hierarchy) layoutSubviews] + 204 16 UIKitCore 0x18f903814 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 2424 17 QuartzCore 0x18ec15498 CA::Layer::layout_if_needed(CA::Transaction*) + 496 18 UIKitCore 0x18f940c10 -[UIView(Hierarchy) layoutBelowIfNeeded] + 312 So far, we only know of one iPad Air M1 where this is happening. But we don't know how many users experience this issue without reporting it. Does anyone know what could cause Auto Layout or Core Animation to block in those calls? We have no clue so far...

Hello everyone, I've been trying for a few weeks now to convert a sequential series of meshes into a stop-motion animation in USDZ format. In Unreal Engine, I’ve already figured out how to transform the sequential series of individual meshes into a smooth animation using the node system and arrays. Unfortunately, the node system cannot be exported as a usdz animation logic in either Unreal or Blender. Because of this, I have tried several other methods to incorporate the animation logic. Here’s what I’ve tried so far: I attempted to create the animation in Blender with Render-/Viewports and mapping it to keyframes. However, in my experience, Viewports are not supported in the conversion. I tried aligning the vertices of individual objects and merging the frames using the Shrinkwrap modifier in Blender, then setting up a morph animation with keyframes. However, because the individual meshes are too different, this results in artifacts, and manually editing each mesh is too difficult for me to handle. I placed all individual meshes at the same position and animated them sequentially by scaling them from 0 to 100 in keyframes (Frame 1 is visible for 10 frames, then scales down at frame 11, while Frame 2 becomes visible at frame 11, and so on). I also adjusted the keyframes so that the scaling happens in a "constant" manner rather than the default Bezier or linear interpolation. I then converted this animation to .abc, and the result initially looked good. However, some information is lost when converting it with OpenUSD. The animation does not maintain its intended jump-like behavior in USDZ format, and instead, the scaling of individual files is visible in the animation. I tried using a Blender add-on (StepMotion), which allows the animation to be exported as .abc, but it can only be read in Blender or Unreal. Even in the preview, the animation is not displayed correctly, so converting the animation logic does not work either. 
Unfortunately, I have no alternative way to create the animation, as the individual frames have been provided to me as meshes. So far, I haven’t found a way to implement this successfully. I would be very grateful for any tips or ideas, as I am running out of options on how to make this work. Thanks in advance!

We've seen a spike in crashes on iOS 18.4 across both iPhone & iPad. We can't reproduce it, but it looks like it happens when the app goes into the background. Crash Log

I want to show a view, where the user can add or remove items shown as icons, which are sorted in two groups: squares and circles. When there are only squares, they should be shown in one row: [] [] [] When there are so many squares that they don’t fit horizontally, a (horizontal) scrollview will be used, with scroll-indicator always shown to indicate that not all squares are visible. When there are only circles, they also should be shown in one row: () () () When there are so many circles that they don’t fit horizontally, a (horizontal) scrollview will be used, with scroll-indicator always shown to indicate that not all circles are visible. When there a few squares and a few circles, they should be shown adjacent in one row: [] [] () () When there are so many squares and circles that they don’t fit horizontally, they should be shown in two rows, squares on top, circles below: [] [] [] () () () When there are either too many squares or too many circles (or both) to fit horizontally, one common (horizontal) scrollview will be used, with scroll-indicator always shown to indicate that not all items are visible. I started with ViewThatFits: (see first code block) { let squares = HStack { ForEach(model.squares, id: \.self) { square in Image(square) } } let circles = HStack { ForEach(model.circles, id: \.self) { circle in Image(circle) } } let oneLine = HStack { squares circles } let twoLines = VStack { squares circles } let scrollView = ScrollView(.horizontal) { twoLines }.scrollIndicators(.visible) ViewThatFits(in: .horizontal) { oneLine twoLines scrollView.clipped() } } While this works in general, it doesn’t animate properly. When the user adds or removes an image the model gets updated, (see second code block) withAnimation(Animation.easeIn(duration: 0.25)) { model.squares += image } and the view animates with the existing images either making space for a new appearing square/circle, or moving together to close the gap where an image disappeared. This works fine as long as ViewThatFits returns the same view. However, when adding 1 image leads to ViewThatFits switching from oneLine to twoLines, this switch is not animated. The circles jump to the new position under the squares, instead of sliding there. I searched online for a solution, but this seems to be a known problem of ViewThatFits. It doesn't animate when it switches... (tbc)

Hi, when I run NavigationSplitView as shown below, the sidebar opens and closes smoothly. struct TestingView: View { var body: some View { NavigationSplitView { Text("Sidebar") } detail: { Text("Detail") } } } However, when I add a minimum width, the sidebar animation starts to lag. I tried various wapping solutions, but I couldn’t get rid of the stutter. struct TestingView: View { var body: some View { NavigationSplitView { Text("Sidebar") } detail: { Text("Detail") } .frame(minWidth: 800) } } As a solution, I had to disable the animation completely: .animation(nil, value: columnVisibility) Is there a way to keep the animation without the stuttering?

Is there some reason UIKit's and AppKit's animate(with:changes:completion:) methods are marked deprecated in iOS 18 when they were also first made available in iOS18? If they are indeed already deprecated, is there a replacement method we are supposed to use? This method allows the developer to use SwiftUI animations to animate UIKit and AppKit views.