I have a UICollectionView using a UICollectionViewCompositionalLayout with an orthogonally scrolling section. When selecting a cell, I present a modal view controller with a zoom transition. If I scroll quickly in that section after dismissing the presented view controller, the cells briefly overlap. See the attached screenshot. This issue occurs only on iOS 26 and does not occur on iOS 18. Has anyone found a way to mitigate this? Sample project: https://github.com/antiraum/iOS26_UICollectionViewZoomTransitionIssue Feedback FB21022192

After switching our iOS app project from Swift 5 to Swift 6 and publishing an update, we started seeing a large number of crashes in Firebase Crashlytics. The crashes are triggered by NotificationCenter methods (post, addObserver, removeObserver) and show the following error: BUG IN CLIENT OF LIBDISPATCH: Assertion failed: Block was expected to execute on queue [com.apple.main-thread (0x1f9dc1580)] All scopes to related calls are already explicitly marked with @MainActor. This issue never occurred with Swift 5, but appeared immediately after moving to Swift 6. Has anyone else encountered this problem? Is there a known solution or workaround? Thanks in advance!

Hello, I’m trying to present my custom SwiftUI dialog with text field in UIKit with modalPresentationStyle = .overFullScreen, but it leads to the UI being completely frozen once I select the TextField and memory constantly leaking. The minimal reproducible code is: class ModalBugViewController: UIViewController { var hostingController: UIHostingController<Content>! struct Content: View { @State private var text = "" var body: some View { ZStack { Color.black.opacity(0.5).ignoresSafeArea() VStack { TextField("Test", text: $text) .textFieldStyle(.roundedBorder) .padding() } } } } override func viewDidLoad() { super.viewDidLoad() view.backgroundColor = .clear hostingController = UIHostingController(rootView: Content()) addChild(hostingController) view.addSubview(hostingController.view) hostingController.view.translatesAutoresizingMaskIntoConstraints = false NSLayoutConstraint.activate([ hostingController.view.topAnchor.constraint(equalTo: view.topAnchor), hostingController.view.bottomAnchor.constraint(equalTo: view.bottomAnchor), hostingController.view.leadingAnchor.constraint(equalTo: view.leadingAnchor), hostingController.view.trailingAnchor.constraint(equalTo: view.trailingAnchor) ]) hostingController.didMove(toParent: self) } } And then in UIKit source view: let viewController = ModalBugViewController() viewController.modalPresentationStyle = .overFullScreen present(viewController, animated: true) The bug is reproducible on iOS 18 - 26.1, even on the simulator, although on iOS 26 it's in landscape mode only. Is there some workaround for this issue that doesn't involve rewriting the whole dialog in UIKit?

I am experiencing a frustrating bug on iOS 26.1 that makes my app look as if it lacks attention to detail. Basically, when having a NavigationStack, where the root view has a top-right confirmation bar button item, and a pushed detail view does not have any button in the navigation bar trailing position, upon poping back to the root view, the confirmation bar button item shows a white overlay for about 1-2 seconds before finally disappearing and showing the correct appearance. Here is the incorrect appearance right after the pop transition: Eventually after about 1,5 seconds it gets turned back to what it should look like: Here is the full code that you can use to reliably reproduce this issue on iOS 26.1: @State private var path: [Int] = [] var body: some View { NavigationStack(path: $path) { VStack { Text("First View") .font(.title) } .navigationDestination(for: Int.self, destination: { param in Text("Detail View") .font(.title) }) .navigationTitle("First") .navigationBarTitleDisplayMode(.inline) .toolbar { ToolbarItemGroup(placement: .confirmationAction) { Button("Next", role: .confirm, action: { self.path.append(1) }) } } } } } I submitted a Feedback for it: FB21010613 . Is there anything at all I can do on my end to work around this issue?

I want to scale the Image. If my Image (or GIF) is 11x33 (width=3 and height=11) but I want the Image size be 220x660 and how to auto expand the pixel? the pixel (0,0) in my image will be a 20x20 with same color. which means the Image(which I want) will has a pixel(0,0) to (20,20) is the same color to the (0,0)

I have following code and made it invoke every time when a UIViewController presents another UIViewController through method swizzling. When I try to access the Password management app while input password, these code will be invoked and the presenting VC is instance of UITrackingElementWindowController. It will crash [presentingVC beginAppearanceTransition:NO animated:NO]; [presentingVC endAppearanceTransition];

From what I understand, you’re meant to pass information like a view model to a content view through its configuration state. What about callbacks (e.g. something like didClickButton)? They aren’t “inputs” into the content configuration like a view model would be, but it feels odd to create and apply a content configuration only to specify callbacks and nothing else.

hello, I have been receiving crash reports on iPadOS 26.1, When UITrackingElementWindowController viewDidDisappear The feedback associated with this post is: FB20986398 and Exception Exception 'Cannot remove an observer <PKTextEffectsWindowObserver 0x10854cbe0> for the key path "frame" from <UITextEffectsWindow 0x10827ca00> because it is not registered as an observer.' #1 0x0000000183529814 in objc_exception_throw () #2 0x00000001845065a4 in -[NSObject(NSKeyValueObserverRegistration) _removeObserver:forProperty:] () #3 0x00000001845069c8 in -[NSObject(NSKeyValueObserverRegistration) removeObserver:forKeyPath:] () #4 0x00000001845068e0 in -[NSObject(NSKeyValueObserverRegistration) removeObserver:forKeyPath:context:] () #5 0x00000001cb22e894 in -[PKTextEffectsWindowObserver dealloc] () #6 0x000000018beafb28 in _setInteractionView () #7 0x000000018d81e8b8 in -[UIView(Dragging) removeInteraction:] () #8 0x00000001cb216448 in -[PKTextInputInteraction willMoveToView:] () #9 0x000000018beafb1c in _setInteractionView () #10 0x000000018d81e8b8 in -[UIView(Dragging) removeInteraction:] () #11 0x000000018d5ab094 in -[UIEditingOverlayViewController _removeInteractions] () #12 0x000000018cb166a8 in -[UIViewController _setViewAppearState:isAnimating:] () #13 0x000000018cb16d70 in __52-[UIViewController _setViewAppearState:isAnimating:]_block_invoke_2 () #14 0x000000018cb16c10 in __52-[UIViewController _setViewAppearState:isAnimating:]_block_invoke () #15 0x000000018655ef78 in __NSARRAY_IS_CALLING_OUT_TO_A_BLOCK__ () #16 0x00000001866b4a24 in -[__NSArrayI enumerateObjectsWithOptions:usingBlock:] () #17 0x000000018cb16a44 in -[UIViewController _setViewAppearState:isAnimating:] () #18 0x000000018cb1753c in -[UIViewController __viewDidDisappear:] () #19 0x000000018cb17638 in -[UIViewController _endAppearanceTransition:] () #20 0x000000018ca2401c in __48-[UIPresentationController transitionDidFinish:]_block_invoke () #21 0x000000018ca23cd0 in -[UIPresentationController transitionDidFinish:] () #22 0x000000018ca2d720 in -[_UICurrentContextPresentationController transitionDidFinish:] () #23 0x000000018ca27608 in __77-[UIPresentationController runTransitionForCurrentStateAnimated:handoffData:]_block_invoke.106 () #24 0x000000018cb31fec in -[_UIViewControllerTransitionContext completeTransition:] () #25 0x000000018d7f09bc in -[UITransitionView notifyDidCompleteTransition:] () #26 0x000000018d7f0750 in -[UITransitionView _didCompleteTransition:] () #27 0x000000018bf1c2a4 in __UIVIEW_IS_EXECUTING_ANIMATION_COMPLETION_BLOCK__ () #28 0x000000018d817960 in -[UIViewAnimationBlockDelegate _didEndBlockAnimation:finished:context:] () #29 0x000000018d7f7168 in -[UIViewAnimationState sendDelegateAnimationDidStop:finished:] () #30 0x000000018d7f75cc in -[UIViewAnimationState animationDidStop:finished:] () #31 0x000000018d7f763c in -[UIViewAnimationState animationDidStop:finished:] () #32 0x0000000186fedda4 in run_animation_callbacks () #33 0x000000010365e2d0 in _dispatch_client_callout () #34 0x000000010367f4c0 in _dispatch_main_queue_drain.cold.5 () #35 0x0000000103654778 in _dispatch_main_queue_drain () #36 0x00000001036546b4 in _dispatch_main_queue_callback_4CF () #37 0x00000001865b42c8 in __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ () #38 0x0000000186567b3c in __CFRunLoopRun () #39 0x0000000186566a6c in _CFRunLoopRunSpecificWithOptions () #40 0x0000000226ee5498 in GSEventRunModal () #41 0x000000018bf2aba4 in -[UIApplication _run] () #42 0x000000018bed3a78 in UIApplicationMain ()

We’re building a hybrid iOS app using Angular (web) rendered inside a WKWebView, hosted by a native Swift app. Recently, we encountered a crash related to UIKeyboardStateManager in UIKit when switching between text inputs continuously within an Angular screen. Scenario The screen contains several text input fields. A “Next” button focuses the next input field programmatically. After about 61 continuous input field changes, the app crashes. It seems like this may be related to UIKit’s internal keyboard management while switching focus rapidly inside a WebView. crash stack: Crashed: com.apple.main-thread 0 WebKit 0xfbdad0 <redacted> + 236 1 UIKitCore 0x10b0548 -[UITextInteractionSelectableInputDelegate _moveToStartOfLine:withHistory:] + 96 2 UIKitCore 0xd0fb38 -[UIKBInputDelegateManager _moveToStartOfLine:withHistory:] + 188 3 UIKitCore 0xa16174 __158-[_UIKeyboardStateManager handleMoveCursorToStartOfLine:beforePublicKeyCommands:testOnly:savedHistory:force:canHandleSelectableInputDelegateCommand:keyEvent:]_block_invoke + 52 4 UIKitCore 0xa36ae4 -[_UIKeyboardStateManager performBlockWithTextInputChangesIgnoredForNonMacOS:] + 48 5 UIKitCore 0xa160f0 -[_UIKeyboardStateManager handleMoveCursorToStartOfLine:beforePublicKeyCommands:testOnly:savedHistory:force:canHandleSelectableInputDelegateCommand:keyEvent:] + 440 6 UIKitCore 0xa07010 -[_UIKeyboardStateManager handleKeyCommand:repeatOkay:options:] + 5760 7 UIKitCore 0xa2fb64 -[_UIKeyboardStateManager _handleKeyCommandCommon:options:] + 76 8 UIKitCore 0xa2fb08 -[_UIKeyboardStateManager _handleKeyCommand:] + 20 9 UIKitCore 0xa30684 -[_UIKeyboardStateManager handleKeyEvent:executionContext:] + 2464 10 UIKitCore 0xa2f95c __42-[_UIKeyboardStateManager handleKeyEvent:]_block_invoke + 40 11 UIKitCore 0x4b9460 -[UIKeyboardTaskEntry execute:] + 208 12 UIKitCore 0x4b92f4 -[UIKeyboardTaskQueue continueExecutionOnMainThread] + 356 13 UIKitCore 0x4b8be0 -[UIKeyboardTaskQueue addTask:breadcrumb:] + 120 14 UIKitCore 0x4a9ed0 -[_UIKeyboardStateManager _setupDelegate:delegateSame:hardwareKeyboardStateChanged:endingInputSessionIdentifier:force:delayEndInputSession:] + 3388 15 UIKitCore 0xfa290 -[_UIKeyboardStateManager setDelegate:force:delayEndInputSession:] + 628 16 UIKitCore 0xf617c -[UIKeyboardSceneDelegate _reloadInputViewsForKeyWindowSceneResponder:force:fromBecomeFirstResponder:] + 1140 17 UIKitCore 0xf5c88 -[UIKeyboardSceneDelegate _reloadInputViewsForResponder:force:fromBecomeFirstResponder:] + 88 18 UIKitCore 0x4fe4ac -[UIResponder(UIResponderInputViewAdditions) reloadInputViews] + 84 19 WebKit 0xfbe708 <redacted> + 100 20 WebKit 0xfbf594 <redacted> + 340 21 WebKit 0x8a33d8 <redacted> + 32 22 WebKit 0x8cee04 <redacted> + 144 23 WebKit 0x1c83f0 <redacted> + 22692 24 WebKit 0x73f40 <redacted> + 264 25 WebKit 0x162c7c <redacted> + 40 26 WebKit 0x1623b4 <redacted> + 1608 27 WebKit 0x73298 <redacted> + 268 28 WebKit 0x72e48 <redacted> + 660 29 JavaScriptCore 0xdb00 WTF::RunLoop::performWork() + 524 30 JavaScriptCore 0xd744 WTF::RunLoop::performWork(void*) + 36 31 CoreFoundation 0xf92c __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 28 32 CoreFoundation 0xf744 __CFRunLoopDoSource0 + 172 33 CoreFoundation 0xf5a0 __CFRunLoopDoSources0 + 232 34 CoreFoundation 0xff20 __CFRunLoopRun + 840 35 CoreFoundation 0x11adc CFRunLoopRunSpecific + 572 36 GraphicsServices 0x1454 GSEventRunModal + 168 37 UIKitCore 0x135274 -[UIApplication _run] + 816 38 UIKitCore 0x100a28 UIApplicationMain + 336 39 APP1 0xa2ed0 main + 21 (AppDelegate.swift:21) 40 ??? 0x1aa889f08 (シンボルが不足しています) From reviewing the crash log, it appears that the crash occurs inside UIKeyboardStateManager while handling keyboard or cursor updates. Questions Has anyone seen this specific crash pattern involving UIKeyboardStateManager? Are there known UIKit or WebKit bugs related to UIKeyboardStateManager when continuously changing focus between text fields (especially in WKWebView)? Any insights or workarounds would be greatly appreciated. Thanks!

In our app, there is a UIWindow makeKeyAndVisible crash, and for now, it appears once, crash stack: the crash detail: crash.txt in the RCWindowSceneManager class's makeWindowKeyAndVisible method, we check and set a window's windowScene and makeKeyAndVisible: public func makeWindowKeyAndVisible(_ window: UIWindow?) { guard let window else { return } if let currentWindowScene { if window.windowScene == nil || window.windowScene != currentWindowScene { window.windowScene = currentWindowScene } window.makeKeyAndVisible() } } and I set a break point at a normal no crash flow, the stack is: why it crash? and how we avoid this, thank you.

Since iPadOS 26.1 I notice a new annoying bug when changing the dark mode option of the system. The appearance of the UI changes, but no longer for view controllers which are presented as Popover. For these view controllers the method "traitCollectionDidChange()" is still called (though sometimes with a very large delay), but checking the traitCollection property of the view controller in there does no longer return the correct appearance (which is probably why the visual appearance of the popover doesn't change anymore). So if the dark mode was just switched on, traitCollectionDidChange() is called, but the "traitCollection.userInterfaceStyle" property still tells me that the system is in normal mode. More concrete, traitCollection.userInterfaceStyle seems to be set correctly only(!) when opening the popover, and while the popover is open, it is never updated anymore when the dark mode changes. This is also visible in the standard Apps of the iPad, like the Apple Maps App: just tap on the "map" icon at the top right to open the "Map mode" view. While the view is open, change the dark mode. All of the Maps App will change its appearance, with the exception of this "Map mode" view. Does anyone know an easy workaround? Or do I really need to manually change the colors for all popup view controllers whenever the dark mode changes? Using dynamic UIColors won't help, because these rely on the "userInterfaceStyle" property, and this is no longer correct. Bugreport: FB20928471

Starting with iOS 18, UITabBarController no longer updates tab bar item titles when localized strings are changed or reassigned at runtime. This behavior worked correctly in iOS 17 and earlier, but in iOS 18 the tab bar titles remain unchanged until the app restarts or the view controller hierarchy is reset. This regression appears to be caused by internal UITabBarController optimizations introduced in iOS 18. Steps to Reproduce Create a UITabBarController with two or more tabs, each having a UITabBarItem with a title. Localize the tab titles using NSLocalizedString(): tabBar.items?[0].title = NSLocalizedString("home_tab", comment: "") tabBar.items?[1].title = NSLocalizedString("settings_tab", comment: "") Run the app. Change the app’s language at runtime (without restarting), or manually reassign the localized titles again: tabBar.items?[0].title = NSLocalizedString("home_tab", comment: "") tabBar.items?[1].title = NSLocalizedString("settings_tab", comment: "") Observe that the tab bar titles do not update visually.

I have an iPad app that supports multiple scenes. I discovered some issues with my app's user interface that I would like to tweak based on whether the user has setup multitasking (in iPadOS 26) as "Full Screen Apps" or "Windowed Apps". Is there any API or way to determine the current iPadOS 26 multitasking setting? I've looked at UIDevice.current.isMultitaskingSupported and UIApplication.shared.supportsMultipleScenes. Both always return true no matter the user's chosen multitasking choice. I also looked at UIWindowScene isFullScreen which was always false. I tried to look at UIWindowScene windowingBehaviors but that was always nil.

Hi, How to enable multitouch on ARView? Touch functions (touchesBegan, touchesMoved, ...) seem to only handle one touch at a time. In order to handle multiple touches at a time with ARView, I have to either: Use SwiftUI .simultaneousGesture on top of an ARView representable Position a UIView on top of ARView to capture touches and do hit testing by passing a reference to ARView Expected behavior: ARView should capture all touches via touchesBegan/Moved/Ended/Cancelled. Here is what I tried, on iOS 26.1 and macOS 26.1: ARView Multitouch The setup below is a minimal ARView presented by SwiftUI, with touch events handled inside ARView. Multitouch doesn't work with this setup. Note that multitouch wouldn't work either if the ARView is presented with a UIViewController instead of SwiftUI. import RealityKit import SwiftUI struct ARViewMultiTouchView: View { var body: some View { ZStack { ARViewMultiTouchRepresentable() .ignoresSafeArea() } } } #Preview { ARViewMultiTouchView() } // MARK: Representable ARView struct ARViewMultiTouchRepresentable: UIViewRepresentable { func makeUIView(context: Context) -> ARView { let arView = ARViewMultiTouch(frame: .zero) let anchor = AnchorEntity() arView.scene.addAnchor(anchor) let boxWidth: Float = 0.4 let boxMaterial = SimpleMaterial(color: .red, isMetallic: false) let box = ModelEntity(mesh: .generateBox(size: boxWidth), materials: [boxMaterial]) box.name = "Box" box.components.set(CollisionComponent(shapes: [.generateBox(width: boxWidth, height: boxWidth, depth: boxWidth)])) anchor.addChild(box) return arView } func updateUIView(_ uiView: ARView, context: Context) { } } // MARK: ARView class ARViewMultiTouch: ARView { required init(frame: CGRect) { super.init(frame: frame) /// Enable multi-touch isMultipleTouchEnabled = true cameraMode = .nonAR automaticallyConfigureSession = false environment.background = .color(.gray) /// Disable gesture recognizers to not conflict with touch events /// But it doesn't fix the issue gestureRecognizers?.forEach { $0.isEnabled = false } } required dynamic init?(coder decoder: NSCoder) { fatalError("init(coder:) has not been implemented") } override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) { for touch in touches { /// # Problem /// This should print for every new touch, up to 5 simultaneously on an iPhone (multi-touch) /// But it only fires for one touch at a time (single-touch) print("Touch began at: \(touch.location(in: self))") } } } Multitouch with an Overlay This setup works, but it doesn't seem right. There must be a solution to make ARView handle multi touch directly, right? import SwiftUI import RealityKit struct MultiTouchOverlayView: View { var body: some View { ZStack { MultiTouchOverlayRepresentable() .ignoresSafeArea() Text("Multi touch with overlay view") .font(.system(size: 24, weight: .medium)) .foregroundStyle(.white) .offset(CGSize(width: 0, height: -150)) } } } #Preview { MultiTouchOverlayView() } // MARK: Representable Container struct MultiTouchOverlayRepresentable: UIViewRepresentable { func makeUIView(context: Context) -> UIView { /// The view that SwiftUI will present let container = UIView() /// ARView let arView = ARView(frame: container.bounds) arView.autoresizingMask = [.flexibleWidth, .flexibleHeight] arView.cameraMode = .nonAR arView.automaticallyConfigureSession = false arView.environment.background = .color(.gray) let anchor = AnchorEntity() arView.scene.addAnchor(anchor) let boxWidth: Float = 0.4 let boxMaterial = SimpleMaterial(color: .red, isMetallic: false) let box = ModelEntity(mesh: .generateBox(size: boxWidth), materials: [boxMaterial]) box.name = "Box" box.components.set(CollisionComponent(shapes: [.generateBox(width: boxWidth, height: boxWidth, depth: boxWidth)])) anchor.addChild(box) /// The view that will capture touches let touchOverlay = TouchOverlayView(frame: container.bounds) touchOverlay.autoresizingMask = [.flexibleWidth, .flexibleHeight] touchOverlay.backgroundColor = .clear /// Pass an arView reference to the overlay for hit testing touchOverlay.arView = arView /// Add views to the container. /// ARView goes in first, at the bottom. container.addSubview(arView) /// TouchOverlay goes in last, on top. container.addSubview(touchOverlay) return container } func updateUIView(_ uiView: UIView, context: Context) { } } // MARK: Touch Overlay View /// A UIView to handle multi-touch on top of ARView class TouchOverlayView: UIView { weak var arView: ARView? override init(frame: CGRect) { super.init(frame: frame) isMultipleTouchEnabled = true isUserInteractionEnabled = true } required init?(coder: NSCoder) { fatalError("init(coder:) has not been implemented") } override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) { let totalTouches = event?.allTouches?.count ?? touches.count print("--- Touches Began --- (New: \(touches.count), Total: \(totalTouches))") for touch in touches { let location = touch.location(in: self) /// Hit testing. /// ARView and Touch View must be of the same size if let arView = arView { let entity = arView.entity(at: location) if let entity = entity { print("Touched entity: \(entity.name)") } else { print("Touched: none") } } } } override func touchesCancelled(_ touches: Set<UITouch>, with event: UIEvent?) { let totalTouches = event?.allTouches?.count ?? touches.count print("--- Touches Cancelled --- (Cancelled: \(touches.count), Total: \(totalTouches))") } }

The document-based SwiftUI example app (https://developer.apple.com/documentation/swiftui/building-a-document-based-app-with-swiftui) doesn't specify a launch image. It would seem per the HIG that the "pinkJungle" background in the app would be a decent candidate for a launch image, since it will be in the background when the document browser comes up. However when specifying it as the UIImageName, it is not aligned the same as the background image. I'm having trouble figuring out how it should be aligned to match the image. The launch image seems to be scaled up a bit over scaledToFill. I suppose a launch storyboard might make this more explicit, but I still should be able to do it without one. This is the image when displayed as the launch image: and this is how it's rendered in the background right before the document browser comes up:

I’m developing an app that includes a navigation bar with a centered title and a single right bar button item. I’ve noticed that when both the navigation bar title and the right bar button item’s title are relatively long, the navigation bar title becomes hidden. This issue only occurs on iOS 26. When running the same code on iOS 18, the layout behaves as expected, with both elements visible. Has anyone else experienced this behavior on iOS 26? Is this a known layout change or a possible bug?

I’m running the interactive reordering sample from this repo and hitting an odd behavior on newer simulators: the delegate method that lets you steer the drop: func collectionView(_:targetIndexPathForMoveOfItemFromOriginalIndexPath:atCurrentIndexPath:toProposedIndexPath:) works fine on iOS 16, but on iOS 18 and iOS 26 simulators it never fires, so the item always lands at the proposed index path and I can’t constrain moves or adjust the compositional view layout to accommodate the cell of different size. Is this a new behavior in modern iOS? If so, what’s the recommended way to control the final index path for the UICollectionViewDropDelegate now?

I have a tab bar with 4 tabs. Since iOS 26, I’m facing an issue with the tab alignment — the text automatically shrinks, and the tab icon shifts upward for some tabs. I am using UITab property for creating Tabs from os Version above 18 and UITabBar for os version below 18.

Hi, We began to get this new crash in codes that exist years ago from our recent released version, it crashed after a view removed itself from superview. We tried to look at the assembly code of NSISSparseVectorAddTermWithPlaceValueCoefficientStartingIndex, find out that d0 <= 0 would branch to NSISSparseVectorAddTermWithPlaceValueCoefficientStartingIndex.cold.1. We believe that it's related with Autolayout, but setting a negative value for width or height constraints can't reproduce this crash. Here is the crash log Exception Type: NSInternalInconsistencyException Invalid parameter not satisfying: placeValue > 0 Exception Codes: fault addr: (null) Crashed Thread: 0 0 CoreFoundation ___exceptionPreprocess + 164 1 libobjc.A.dylib _objc_exception_throw + 88 2 Foundation -[NSMutableDictionary(NSMutableDictionary) initWithContentsOfFile:] + 0 3 CoreAutoLayout NSISSparseVectorAddTermWithPlaceValueCoefficientStartingIndex.cold.1 + 100 4 CoreAutoLayout _NSISSparseVectorAddTermWithPlaceValueCoefficientStartingIndex + 848 5 CoreAutoLayout _NSISSparseVectorAddVectorTimesScalar + 72 6 CoreAutoLayout -[NSISObjectiveLinearExpression replaceVar:withExpression:processVarNewToReceiver:processVarDroppedFromReceiver:] + 200 7 CoreAutoLayout ____substituteOutAllOccurencesOfBodyVar_block_invoke + 504 8 CoreAutoLayout __substituteOutAllOccurencesOfBodyVar + 340 9 CoreAutoLayout __pivotToMakeColNewHeadOfRow + 960 10 CoreAutoLayout -[NSISEngine removeConstraintWithMarker:] + 748 11 CoreAutoLayout -[NSLayoutConstraint _removeFromEngine:] + 140 12 UIKitCore ___57-[UIView(AdditionalLayoutSupport) _switchToLayoutEngine:]_block_invoke + 164 13 CoreAutoLayout -[NSISEngine withBehaviors:performModifications:] + 84 14 UIKitCore -[UIView(AdditionalLayoutSupport) _switchToLayoutEngine:] + 212 15 UIKitCore ___57-[UIView(AdditionalLayoutSupport) _switchToLayoutEngine:]_block_invoke_2 + 148 16 UIKitCore ___57-[UIView(AdditionalLayoutSupport) _switchToLayoutEngine:]_block_invoke + 544 17 CoreAutoLayout -[NSISEngine withBehaviors:performModifications:] + 84 18 UIKitCore -[UIView(AdditionalLayoutSupport) _switchToLayoutEngine:] + 212 19 UIKitCore ___45-[UIView(Hierarchy) _postMovedFromSuperview:]_block_invoke + 84 20 CoreAutoLayout -[NSISEngine withBehaviors:performModifications:] + 84 21 UIKitCore -[UIView _postMovedFromSuperview:] + 512 22 UIKitCore ___UIViewWasRemovedFromSuperview + 136 23 UIKitCore -[UIView(Hierarchy) removeFromSuperview] + 244 Assembly of NSISSparseVectorAddTermWithPlaceValueCoefficientStartingIndex CoreAutoLayout`NSISSparseVectorAddTermWithPlaceValueCoefficientStartingIndex: -> 0x1ec1a2124 <+0>: pacibsp 0x1ec1a2128 <+4>: stp d11, d10, [sp, #-0x60]! 0x1ec1a212c <+8>: stp d9, d8, [sp, #0x10] 0x1ec1a2130 <+12>: stp x24, x23, [sp, #0x20] 0x1ec1a2134 <+16>: stp x22, x21, [sp, #0x30] 0x1ec1a2138 <+20>: stp x20, x19, [sp, #0x40] 0x1ec1a213c <+24>: stp x29, x30, [sp, #0x50] 0x1ec1a2140 <+28>: add x29, sp, #0x50 0x1ec1a2144 <+32>: mov x19, x1 0x1ec1a2148 <+36>: fmov d9, d2 0x1ec1a214c <+40>: fmov d10, d1 0x1ec1a2150 <+44>: fmov d8, d0 0x1ec1a2154 <+48>: mov x20, x0 0x1ec1a2158 <+52>: fcmp d0, #0.0 0x1ec1a215c <+56>: b.le 0x1ec1a2470 ; <+844> 0x1ec1a2160 <+60>: fcmp d10, #0.0 0x1ec1a2164 <+64>: adrp x8, 112778 .... 0x1ec1a2468 <+836>: ldp d11, d10, [sp], #0x60 0x1ec1a246c <+840>: retab 0x1ec1a2470 <+844>: bl 0x1ec1cac18 ; NSISSparseVectorAddTermWithPlaceValueCoefficientStartingIndex.cold.1 0x1ec1a2474 <+848>: b 0x1ec1a2160 ; <+60>

Hello, While integrating the Liquid Glass UI introduced in iOS 26 into my existing app, I encountered an unexpected issue. My app uses a UITabBarController, where each tab contains a UINavigationController, and the actual content resides in each UIViewController. Typically, I perform navigation using navigationController?.pushViewController(...) and hide the TabBar by setting vc.hidesBottomBarWhenPushed = true when needed. This structure worked perfectly fine prior to iOS 26, and I believe many apps use a similar approach. However, after enabling Liquid Glass UI, a problem occurs. Problem Description From AViewController, I push BViewController with hidesBottomBarWhenPushed = true. BViewController appears, and the TabBar is hidden as expected. When performing a swipe-back gesture, as soon as AViewController becomes visible, the TabBar immediately reappears (likely due to A’s viewWillAppear). The TabBar remains visible for a short moment even if the gesture is canceled — during that time, it is also interactable. Before iOS 26, the TabBar appeared synchronized with AViewController and did not prematurely show during the swipe transition. Tried using the new iOS 18 API: tabBarController?.setTabBarHidden(false, animated: true) It slightly improves the animation behavior, but the issue persists. If hidesBottomBarWhenPushed is now deprecated or discouraged, migrating entirely to setTabBarHidden would require significant refactoring, which is not practical for many existing apps. Is this caused by a misuse of hidesBottomBarWhenPushed, or could this be a regression or design change in iOS 26’s Liquid Glass UI?