iOS 13 Developer Beta 1 Available for iPhone with a Lot of Kinks to Work Out

The first developer beta for iOS 13 is available to install on iPhone models, but the process for doing so may be a bumpy ride. Apple has not included configuration profiles for the developer beta yet, and many developers are having issues installing iOS 13 even with macOS 10.15 Catalina installed. Plus, since this is the first beta, there are a lot of problems with old and new features to work the kinks out of.

Apple's release notes for iOS 13 developer beta 1 — which also includes iPadOS 13 developer beta 1, since iPad and iPhone are now split off into their own somewhat distinct operating systems — have a lot of known issues with new features, old features, and things only concerning app development and overall stability.

Overall, Apple reports almost 140 issues to deal with, meaning, this shouldn't be deployed your daily driver. While small issues with Photos and Podcasts and other apps, problems with Wi-Fi calling, SIMs, LTE, and FaceTime may convince you not to try out iOS 13 right away. However, there are over 100 new features residing in iOS 13, so the risk may be worth it, it's your choice.

• Update: iOS 13 Developer Beta 2 Now Available for iPhone

If you'd like to give iOS 13 dev beta 1 a try, follow our install iOS 13 guide. But make sure you read all of the release notes below before committing to an early beta.

Overview

This version is intended exclusively for software developers to test their apps and start adopting the new technologies in iOS. Make sure to back up your device and install only on systems you are prepared to erase if necessary.

Important Note for Thrill Seekers: If you're interested in living on the edge and trying out the great new features in iOS & iPadOS 13, we strongly advise waiting for the many bug fixes and refinements coming to the public beta later this month.

General - Known Issues

• To edit your widgets, you might need to rotate iPad to landscape orientation. (49162249)
• The EU volume limit warning might not appear when exceeding the maximum volume limit. (51068683)
• When AirPlay mirroring is used with certain apps, the mirrored output might produce unexpected results. (51116513)
• Following an update to iOS & iPadOS 13, users with large photo libraries might need to wait for an extended period while their device displays the Apple logo with a progress bar. (51147659)
• If Face ID stops working unexpectedly, restart your device and try again. (51205195)
• macOS 10.15 beta or Xcode 11 beta is required to sync or update a device running iOS & iPadOS 13. (51325292)

General - Deprecations

• The UIApplicationExitsOnSuspend key is no longer supported in iOS & iPadOS 13. Update your apps to handle modern multitasking. (43958234)

Accessibility - Known Issues

• When Reduce Transparency is enabled, AVPlayerViewController might not display video correctly. (51144377)

Activity - Known Issues

• Activity might quit unexpectedly when viewing Trends on the last day of the month. (51299302)
• Friend Activity Sharing history might list inaccurate calorie counts. (51265705)

App Store - Known Issues

• SKStoreProductViewController currently returns a blank page. (50955943)

Apple CryptoKit - Known Issues

• When using the SecureEnclave API with access control set on keys, users might not be prompted to authenticate. This might cause subsequent operations requiring authentication to fail. (51279188)

Audio - New Features

• Voice Processing mode can now be enabled on AVAudioEngine. (50906329)
• New AVAudioNode types can be used to wrap a user-defined block for sending or receiving data in real time.
• A new method is available for an AVAudioEngine-based app to retrieve a list of all nodes attached to an AVAudioEngine instance.
• A new rendering mode in AVAudioEnvironmentNode selects the best spatial audio rendering algorithm automatically based on the output device.
• A new AVAudioSession property allows system sounds and haptics to play while the session actively uses audio input.
• A new enumeration, AVAudioSession.PromptStyle, informs apps which style of voice prompt they should play based on other audio activity in the system.
• AVAudioSession.RouteSharingPolicy now permits apps to specify route-sharing policies so their audio and video routes to the same location as AirPlay.
• Audio Unit Extensions now support user presets that are available across all host applications.

Audio - Known Issues

• Some real–time audio applications might exhibit audio artifacts. (50870425)

Audio - Deprecations

• The OpenAL framework is deprecated and remains present for compatibility purposes. Transition to AVAudioEngine for spatial audio functionality.
• AUGraph is deprecated in favor of AVAudioEngine.
• Inter-App audio is deprecated. Use Audio Units for this functionality moving forward.
• Carbon component-based Audio Units are deprecated and support will be removed in a future release.
• Legacy Core Audio HAL audio hardware plug-ins are no longer supported. Use audio server plug-ins for audio drivers moving forward.

Audio Sharing - New Features

• Audio sharing is compatible with AirPods (1st generation or later) and PowerBeats Pro. iPhone 8 or later, iPad Pro 12.9-inch (2nd generation or later), iPad Pro 11-inch, iPad Pro 10.5-inch, iPad (5th generation or later), iPad Air (3rd generation), iPad mini (5th generation), or iPod touch (7th generation or later) is required. (51331268)

Audio Sharing - Known Issues

• Initiating a phone call using Siri from one device might result in the call being routed to the other device. (50792780)
• Adjusting the volume level during audio sharing might produce unexpected results. (50967849)
• If an audio device disconnects unexpectedly during audio sharing, it might not reconnect. Restart your iOS device and try connecting again. (51037861)

AVFoundation - New Features

• AVFoundation now supports encoding video with alpha channels using HEVC. Videos encoded in this manner are broadly supported in AVFoundation APIs, and by Safari within web pages. Technical details of the format can be found in the Interoperability Profile specification. (8045917)

AVFoundation - Known Issues

• Long-form video apps using the AVInitialRouteSharingPolicy Info.plist key might exhibit inconsistent AirPlay route suggestions. Manually route to an AirPlay-capable TV using an in-app AVRoutePickerView or by using the Now Playing control in Control Center to test AirPlay and adoption of prepareRouteSelectionForPlayback(completionHandler:). (50924593)

Books - Known Issues

• Books and PDFs imported into the Books app might not upload to iCloud Drive. (47124224)
• Books stored in iCloud Drive might not appear in Books. (48685806)

CarPlay - Known Issues

• The state shown on the garage door button might be incorrect when it first appears in the CarPlay Dashboard. (49282265)
• Images within navigation apps might display at unexpected sizes. (49380030)
• To return to the Home screen from the Maps widgets screen, tap the button in the lower left corner of the screen. (50855855)
• You might need to launch Maps before asking Siri for directions. (50860819)
• If your iPhone displays a blank screen after using CarPlay, pull down Notification Center then swipe up to unlock. (51164072)

Core Haptics - Known Issues

• By default, haptics are disabled when microphone recording begins. You can override this by setting the AVAudioSession property allowHapticsAndSystemSoundsDuringRecording to true before activating its audio session. (25811898)
• Events — such as audioContinuous, hapticContinuous, and audioCustom — can't be resumed during the event; no output occurs for that event, only for subsequent events. This applies to playback at a specific time offset, seeking, and resuming. (29274583)
• When audio generated by Core Haptics is played using an audio session category or mode that normally supports Bluetooth or wired headphone output, no audio plays. (29939183, 50905288)
• CHHapticDynamicParameter instances with nonzero relative times that are sent as part of a sendParameters(_:atTime:) call on a CHHapticAdvancedPatternPlayer with the atTime parameter set to 0.0 are incorrectly applied at the beginning of the CHHapticPattern, instead of the expected nonzero relative time. This doesn't occur on a CHHapticPatternPlayer. (46316890)
• Both vibrations generated through AudioServicesPlaySystemSound(_:) and vibration patterns generated through the user-created tap-to-vibrate UI are attenuated when compared to prior versions of iOS. (47448156)
• Parameter Curves are not supported with a CHHapticAdvancedPatternPlayer, only a CHHapticPatternPlayer. No error is generated when a CHHapticPattern containing a Parameter Curve is passed to a CHHapticAdvancedPatternPlayer. (47891515)
• Brief audio distortion occurs when starting a Playback category app such as Music in the background. For example, brief distortion occurs if you start the app from Control Center while Core Haptics audio playback using a playAndRecord audio session is already underway. (48121467)
• Following any decompression to uncompressed floating-point samples, the total limit on all audioCustom resources per process is eight megabytes. (48659023)
• Multiple overlapping Parameter Curves for the same CHHapticDynamicParameter.ID might result in playback artifacts. (50026384)
• The default value for audioBrightnessControl should be 0, not 1. (50310604)
• Creating a hapticContinuous event with an attackTime of 1.0, and then dynamically increasing the attack time by 1.0, causes erroneous behavior. The expected behavior is the attack time should saturate at 1.0; therefore increasing the attack on an event that already has maximum attack (1.0) should have no effect. (50386282)
• Starting a CHHapticPatternPlayer multiple times results in multiple playbacks stacked together, instead of restarting playback. (50878861)
• The maximum duration for a hapticContinuous haptic event is 30 seconds. Events exceeding this limit can be constructed and accepted by CHHapticPatternPlayer, but haptic playback will fade out after 30 seconds. (51322525)

Core Image - New Features

• The init(imageURL:options:) and init(imageData:options:) initializers no longer support RAW version 5 and earlier. Version 6 and later remain supported. (50911303)
• Added new APIs for instantiating and modifying the built-in Core Image filters.
• The CICoreMLModel filter is enhanced to support models with an input or output of type MLFeatureType.multiArray.
• Metal CIKernel instances support arguments with arbitrarily structured data.
• Metal CIKernel instances support returning a group of 2 × 2 pixels.
• The integer values of CIFormat symbols, such as ARGB8, have changed to a new set of values that are consistent across platforms. The former values remain supported for backward compatibility; however, you should avoid dependancies on specific numerical values.

Core Media - Known Issues

• You might experience interruptions when attempting to play Amazon Prime Video. (46791204)
• Support for low-latency HLS isn't yet available in iOS & iPadOS 13 beta. (51241703)

Core ML - Known Issues

• In the MLRecommender model, the exclude and restrict parameters are required, but they should be optional. For default behavior, pass in an empty list for restrict and the list of query items for exclude. (50348777)

Device Management - Known Issues

• After completing User Enrollment you might be prompted to reenter your Managed Apple ID credentials when viewing account details in Settings > Passwords & Accounts. (48605466)
• After completing User Enrollment, Reminders can't be enabled for the Managed Apple ID. (48820760)
• On User Enrollment, Notes might not show data for the enterprise account until the device is restarted. (49833240)
• MDM can't install enterprise apps on Chinese devices until the App Store is approved to use WLAN connection. (50785136)
• Users can't accept an invitation to App and Book Assignments. (50832260)
• MDM queries might return unmanaged data, such as profiles and certificates installed using Apple Configurator. (50857952)
• MDM servers will return a server error instead of a license not found error when installing Volume Purchase Program (VPP) apps without a license assigned. (50905338)
• Installing apps using MDM with purchase method set to none will fail If the app isn't already in the user's purchase history. (50909360)
• On a User Enrollment, you might be unable to install enterprise apps after removing and then reenrolling in MDM. (50959631)
• The Enterprise iCloud Drive will be inaccessible from managed apps when the managed "Open-in" restriction is enabled on a User Enrollment. (51016087)

Files - Known Issues

• Using Files in Schoolwork isn't currently supported. (50114382, 50709151)
• Apps might not appear as expected within Files. (50539041)
• If the layout of documents browser ends up in an inconsistent state, toggle the view options. (51160246)
• Attempting to connect to SMB servers from Files and from apps using UIDocumentBrowserViewController currently produces an error message. (50987682)
• APFS formatted drives aren't currently supported. (51071338)

Find My - Known Issues

• When performing an action in Find My that generates an email, you might see references to the Find My Friends and Find My iPhone apps. (51123613)
• The "Notify when found" feature is currently unavailable.
• Apple Pay cards might remain suspended after a device exits Lost Mode.
• While iOS & iPadOS 13 remains in beta, offline-finding capability is limited.
• The "Repeat Every Time" option for location notifications is currently unavailable. (51271728)

Home Screen - Known Issues

• Tapping on a Continuity Handoff suggestion while the suggested app is in the foreground results in app exposé rather than the Continuity Handoff suggestion. (47974821)
• If the Quick Action menu is invoked on an app that has a badged icon, the badge layers behind the icon until the Quick Action menu is dismissed. (48374339)
• Dragging app icons from Spotlight currently has no effect. Instead, drag app icons from the Dock. (49004339)
• The Files document popover on the Home screen doesn't expand or scroll. (49087149)
• When using right-to-left languages, opening a folder from the Home screen containing multiple pages of apps will launch unexpectedly to the leftmost page rather than the rightmost page. (50365467)
• On the lock screen, you can't adjust playback volume while a track is paused. (50389611)
• Some items in Quick Action menus have unexpectedly large icons. (50561570)
• When the user drags content into Split View or Slide Over, targetContentIdentifiers and UISceneActivationConditions predicates aren't used to select an appropriate window scene. (50784657)
• When viewing widgets for the first time after restarting your device, the Show More toggles might not appear until you exit and reopen the widget view. (50966601)
• While Airplane Mode is enabled, you might be prompted to turn Wi-Fi on even though it's already on. (51080243) Workaround: Instead of using Airplane Mode, disable Cellular Data.

iCloud - Known Issues

• If you receive an error trying to sign into iCloud while attempting to restore from a backup, tap Skip, then resume signing into iCloud once the restore completes. (49716545)
• The iCloud Drive section in Settings > General > iPhone Storage might inaccurately represent the current state of files on your device. (50362095)
• Pages, Numbers, and Keynote documents in shared folders can only be opened on macOS and iOS. iWork documents in shared folders are currently unavailable from iCloud.com. (50738067)
• When creating a new Pages, Numbers, or Keynote document in a shared folder, you might see the message: "Couldn't connect to iCloud." (50827963) Workaround: Close and reopen the document.
• Cloud content might not appear in some applications until the Files app is opened at least once after updating to iOS & iPadOS 13 beta. (50903924)
• When manually initiating iCloud backup from Settings > iCloud Account > iCloud > iCloud Backup > Back Up Now, the progress bar doesn't complete. However, this doesn't mean that the backup isn't complete. Once the text below the progress bar changes from "Backing Up" to "Updating iCloud," it indicates that the backup completed. However, the iCloud sync doesn't complete due an issue with notes syncing with iCloud. Your notes might not be up to date on iCloud compared to the notes on your device. (51030266)

Keyboards - Known Issues

• When multiple keyboard languages are enabled, tapping blue underlined dictated text to correct it might present text replacement suggestions in an unexpected language. (50777944)

Localization - Known Issues

• Devices set to use certain languages might exhibit clipped or misaligned layout. (51068688)
• Devices set to use certain languages might display unlocalized text. (47765173, 51197936, 51270878)

Mail - New Features

• Ignore Blocked Senders can now be enabled in Settings > Mail. The blocked contacts list is shared with Messages, FaceTime, and Phone. (50775961)

Mail - Known Issues

• Mail might quit unexpectedly when turning on Voice Control or when using VoiceOver, Switch Control, or Full Keyboard Access to reply to an email. (51023095)

Maps - Known Issues

• If Picture in Picture doesn't load when using Look Around, move to another location on the map and try again. (50669005)
• When sharing a trip ETA, the receiver might not see the blue route line displayed on the map. (50904902) Workaround: Tap to view the shared trip from the Maps Home screen rather than from the Notification Center banner.
• Maps might quit unexpectedly when selecting a new time within the transit schedule view. (50974490)
• If the current viewing location isn't displayed on the map when using Picture in Picture mode, tap Done and try again. (51070503)
• Tapping a maps.apple.com URL might open Safari before opening Maps. (51095623)
• When using Look Around in Picture in Picture mode, tapping a point of interest on the map might not function correctly. (51096818)

Memoji - Known Issues

• For best results, open the Memoji editor from within Messages. (50968307)

Messages - Known Issues

• The Messages icon might display an exclamation mark before you first open it. (48490814)
• The Messages section in Settings > General > iPhone Storage shows an inaccurate size and the details view doesn't display content to view or delete. (45913540)

Networking - New Features

• All URLSessionTask instances with a GET HTTP method that contain a body now produce the error NSURLErrorDataLengthExceedsMaximum. (46025234)

Networking - Deprecations

• Removed support for FTP and File URL schemes for Proxy Automatic Configuration (PAC). HTTP and HTTPS are the only supported URL schemes for PAC. This affects all PAC configurations including, but not limited to, configurations set using Settings, System Preferences, Profiles, and URLSession APIs such as connectionProxyDictionary and CFNetworkExecuteProxyAutoConfigurationURL(::::). (28578280)
• The URLSession and NSURLConnection APIs no longer support SPDY. Servers should use HTTP 2 or HTTP 1.1. (43391641)
• Your device might be unable to join certain hidden Wi-Fi networks. (51005457)

Notes - Known Issues

• Using search in Notes might produce unexpected results. (48238242)
• Notes might not sync with iCloud. (51047383)
• Certain notes may become illegible when the Increase Contrast accessibility setting is enabled. (51188715)

PencilKit - Known Issues

• PKCanvasView doesn't use the opacity and background color settings from Interface Builder. (50870664)

Phone and FaceTime - Known Issues

• Wi-Fi calls might drop when transitioning from Wi-Fi to a cellular network. (50521720)
• During the initial setup of a device running iOS & iPadOS 13 beta, you might need to remove and reinsert the SIM card in order to reach the PIN entry prompt if SIM PIN is enabled. (50567332)
• When LTE is enabled for Voice & Data (VoLTE), the 2G or 3G cellular data switch might be hidden. (50978364)
• You might be unable to transfer calls between devices that share the same iCloud account. (51037256)
• Attempting to take a FaceTime Live Photo of another user during a Group FaceTime call might cause the remote user to be disconnected from the call. You can prevent this by disabling FaceTime Live Photos in Settings > FaceTime. (51197915)

Photos - Known Issues

• When Autoplay Videos and Live Photos is enabled in Settings > Photos, content downloads using your cellular connection when your iOS device isn't connected to a Wi-Fi network. (47214673)
• Sometimes tapping a sharing suggestion in Photos doesn't allow the photo to be shared. (51200976)

Podcasts - Known Issues

• Transcript search isn't currently available. (50425804)
• Podcast artwork might unexpectedly overlap other UI elements. (50859386)

RealityKit - Known Issues

• Objects appear immediately at a destination when using any animation timing function other than linear() within move(to:relativeTo:duration:timingFunction:). (50999980)

Safari and WebKit - Known Issues

• Open tabs might not be preserved when performing a migration from one device to another. (50975729)
• Keyboard shortcuts might not work when using non-English language settings. (50979111)

Screen Time - Known Issues

• Users can select "One more minute" multiple times per day instead of only once each time they reach the limit for an app. (48773803)
• If you enable Share Across Devices, Screen Time settings don't sync with iCloud until your iOS device is restarted. Any edits you make to your Screen Time settings on that device before restarting are lost. (50194586)
• Messages, FaceTime, and Phone don't currently enforce Screen Time's Communication Limits. (50876617, 51055350, 51055448)

Sign In with Apple - Known Issues

• Sign In with Apple might unexpectedly appear on unsupported sites. (50869308)

Siri - Known Issues

• When you edit an app's intent definition file and install the app, changes aren't immediately reflected in Shortcuts. (46645833) Workaround: Quit and relaunch Shortcuts after installing a new version of the app, or build and run the intents extension in Xcode, targeting the Shortcuts app.
• The supportsOnDeviceRecognition property always returns false the first time it's accessed. After a few seconds, accessing it again returns the correct value. (47822242)
• Siri might be unable to perform actions related to Mail messages. (48140181)
• To properly support Announce Messages with Siri in your messaging app, add INSearchForMessagesIntentIdentifier to your notification category. (50462393)
• You might be unable to create a reminder at a location that isn't a labeled address, such the address labeled Home in your Me card. (50487978)
• Shortcuts synced to a device running iOS & iPadOS 13 beta from iOS 12 via iCloud Sync don't function correctly. (50557374) Workaround: To import an existing set of shortcuts, upgrade a device from iOS 12 to iOS & iPadOS 13 beta instead of erasing then installing. Alternatively, disable iCloud sync on iOS & iPadOS 13 beta, enable Allow Untrusted Shortcuts in Settings > Shortcuts, and use the Share button to share the shortcuts individually from the device running iOS 12.
• Shortcuts are currently unavailable when using Siri on Apple Watch, HomePod, and CarPlay. (50782908)
• Shortcuts opened on iOS & iPadOS 13 beta are automatically upgraded and can no longer be opened on iOS 12. If a device with iOS 12 and a device with iOS 13 share an iCloud account, shortcuts might become unusable on the device running iOS 12. (50873839) Workaround: Disable iCloud Sync between devices running iOS & iPadOS 13 beta and devices running iOS 12.
• While using non-English languages, asking Siri to perform actions related to Reminders or Messages might cause the corresponding application to quit unexpectedly. (50952938)
• Shortcuts added to Siri in iOS 12 might not appear after upgrading to iOS & iPadOS 13 beta. (50957532)
• Currently, the only supported response for INSearchForMediaIntent is INSearchForMediaIntentResponseCode.continueInApp. (51010311)
• Shortcuts-enabled media apps incorrectly appear to have SiriKit Media support and subsequently produce an error. (51010590)
• When Announce Messages with Siri is enabled, music playback might be interrupted when a message is read. (51243455)

SwiftUI - Known Issues

• Return types for View modifier methods include complex generic types. In a future release, these methods will return simpler types. (46140669)
• Tabs in TabbedView instances are blank if you use them with a NavigationView. (49958869)
• Image instances don't use resizing information configured in asset catalogs. Configure the size of an image using the resizable(capInsets:resizingMode:) modifier instead. (49114577)
• The possible values that you can select from a Picker can't be accessed from UI automation. (50679414)
• A ScrollView doesn't always size itself as expected for its content. (49204262) Workaround: Size the view that's inside the ScrollView by applying the frame(width:height:alignment:) modifier to the inner view. (49204262)

Third-Party Apps - Known Issues

• WhatsApp might quit unexpectedly when forwarding messages to a user who isn't in the recent contacts list. (45416129)
• WhatsApp users might receive duplicate notifications or notifications without content. (50537131)
• Didi might not display map data. (48386075)
• Audio might not play in Instagram stories. (50433755)
• The Wells Fargo app might quit unexpectedly when opened or during sign-in. (51085418)

UIKit - New Features

• The UITableViewCell class no longer changes the backgroundColor or isOpaque properties of the contentView and any of its subviews when cells become highlighted or selected. If you are setting an opaque backgroundColor on any subviews of the cell inside (and including) the contentView, the appearance when the cell becomes highlighted or selected might be affected. The simplest way to resolve any issues with your subviews is to ensure their backgroundColor is set to nil or clear, and their opaque property is false. However, if needed you can override the setHighlighted(:animated:) and setSelected(:animated:) methods to manually change these properties on your subviews when moving to or from the highlighted and selected states. (13955336)
• Since iOS 8, using UISearchController with UINavigationController has required setting the definesPresentationContext property of the top view controller to true. Failure to do so leads to subtle bugs that can be hard to detect and debug. Starting in iOS & iPadOS 13 beta, if a view controller's navigationItem has a non-nil searchController, when the view controller is shown in a navigation controller, UINavigationController automatically sets that view controller's definesPresentationContext property to true. If you are targeting earlier versions of iOS, set this property before your search controller becomes active. (31338934)
• The UIRefreshControl class no longer directly modifies the contentInset of its scroll view. Instead, its adjustments to the content inset will be incorporated into the scroll view's adjustedContentInset. The only exception is when the scroll view's contentInsetAdjustmentBehavior is set to UIScrollView.ContentInsetAdjustmentBehavior.never, in which case the UIRefreshControl instance will modify the contentInset directly as it did in previous releases. (35866834)
• If you implement self-sizing cells in a UITableView by overriding sizeThatFits(:) without using Auto Layout, the height you return is interpreted as the desired height for the contentView of the cell, and UITableViewCell automatically adds any additional height needed to allow room for the cell separator. If you implement manual self-sizing this way, the cell's contentView width is guaranteed to be accurate for you to use in manual layout calculations when sizeThatFits(:) is called on the UITableViewCell. (39742612)
• Trait environments, such as views and view controllers, now have their traitCollection property populated with traits during initialization. These initial traits represent a prediction of the ultimate traits that the trait environment will receive when it gets added to the hierarchy. Because the traits that are populated during initialization are just a prediction, they might differ from the traits that are received once actually in the hierarchy. Therefore, when possible you should wait to perform work that uses the traitCollection until the view, or view controller's view, has moved into the hierarchy — meaning window returns a non-nil value — so that you don't have to throw away any work done using the predicted traits if the actual traits are different. The best time to use the traitCollection is during layout, such as inside layoutSubviews(), viewWillLayoutSubviews(), or viewDidLayoutSubviews().
• The traitCollectionDidChange(:) method is only called when the value of a trait changes. Importantly, because the trait collection is now initialized to a prediction of the ultimate traits in the destination hierarchy, when the initial predicted traits match the ultimate traits in the hierarchy, traitCollectionDidChange(:) will not be called when the trait environment is added to the hierarchy. Because traitCollectionDidChange(_:) is intended to be an invalidation callback to notify you that one or more traits changed, audit your existing implementations of this method, as well as the UIContentContainer method willTransition(to:with:), for places where you might have been relying on it to trigger initial setup. The best place to lazily perform work that uses the traitCollection is inside one of the layoutSubviews methods discussed above, but remember that these layout methods are called any time layout occurs so be sure to avoid repeating work when you don't need to. (46818941)
• You can now enable debug logging to easily see when traitCollectionDidChange(_:) or willTransition(to:with:) is called on your own classes. Turn on the logging by using the following launch argument: -UITraitCollectionChangeLoggingEnabled YES. You might want to temporarily disable the Main Thread Checker while using this launch argument and running your app from Xcode to avoid extra log messages for unrelated classes. (47858564)
• The UITableViewCell class's contentView property is always laid out edge-to-edge with adjacent accessories, both on the leading and the trailing side. This streamlines the layout code so developers who want the correct default offset no longer have to align their content with the content view border or the layout margin depending on whether there is an accessory on the trailing side or not. You should now always lay out their code on the layout margins of the cell's content view to get the default system insets. These insets will be adjusted automatically based on the accessories visible in the cell to match the system's default spacing. (48214114)
• You can now invoke a custom initializer from a creation block that's passed through instantiateInitialViewController(creator:) or instantiateViewController(identifier:creator:). This makes it possible for you to initialize view controllers with additional context and arguments, while taking advantage of defining them in a storyboard through Interface Builder. A custom controller initializer must call its super.init(coder:) method and pass the coder argument that it receives through the creation block. (48313869)

UIKit - Known Issues

• Specifying UIWindowScene.DestructionRequestOptions in Swift is currently unavailable. (51036709)

Voice Control - Known Issues

• After you enable Voice Control for the first time, resources begin downloading in the background. Once the download completes, you will receive a notification that Voice Control is ready for use. (50788121)

Watch - Known Issues

• If you pair more than one Apple Watch with your iPhone, you're unable to switch the active connection. (51271140)

Xcode - New Features

• CAMetalLayer is now available in the Simulator. (45101325)

Xcode - Known Issues

• In the Simulator, Siri can't be activated using the Hardware > Siri menu item. Instead, activate Siri by clicking and holding down the lock or home button. Alternatively, if you're testing an intents extension, you can fill in a Siri Intent Query when using Siri as the run target. (48048890)
• You might be unable to create new documents in the Simulator. (50443693)
• Swift interfaces for several new URLSession APIs are unavailable. (50517967)
• To enable Dark Mode in Simulator, open Settings > Developer. (50699968)
• Changing the volume level in Simulator while a video is playing in Safari mutes the audio. (51207286)

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