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macOS Big Sur: 20A4299v Release Notes

macOS Big Sur

Notes and Known Issues


Known Issues

Important: Updating to macOS Big Sur 11 beta from previous versions of macOS might take significantly longer than expected. Data loss could occur if the update is interrupted. (59101197)

Third-Party Apps

Known Issues
  • CMake might not run, install, or might generate invalid outputs. (62905973)Workaround: Update to CMake 3.18rc1.


Known Issues
  • VoiceOver might be unavailable at certain times while installing macOS Big Sur 11 beta. (63025357)

App Store

New Features
  • SKStoreProductViewController and SKProductStorePromotionController APIs are now available for both macOS and Mac Catalyst apps. (56300909)


  • See AppKit Release Notes for macOS Big Sur 11 .

Auto Unlock

Known Issues
  • You might be unable to set up Auto Unlock. (64120075)


Known Issues
  • If you click the Directions button on a calendar notification, Maps might not launch as expected. (63697152)
  • It isn’t possible to edit Calendar widgets. (63984003)
  • Accounts might not be visible in Preferences. (64117985)


Known Issues
  • Continuity Handoff isn’t currently available in macOS Big Sur 11 beta. (64140413)

Core ML

Known Issues
  • When setting isSynchronizationEnabled to true on a MLModelCollection , the initial download may take longer than expected to complete. The collection then becomes available. (64131243)
  • The default initializer on the auto-generated model interface has been deprecated in favor of init(configuration:). Please use init(configuration:) or the newly introduced .load() method and handle model load errors as appropriate. (64432588)

Desktop Picture

Known Issues
  • If the desktop picture was never changed from the default macOS Catalina 10.15 image, it will persist after updating to macOS Big Sur 11 beta, even though the new default desktop picture is displayed in Desktop and Screen Saver preferences. (64390185)

Installer and Software Update

Known Issues
  • If you updated to macOS Big Sur 11 beta from a previous version of macOS, Software Update might show “Unable to check for updates – Failed to download the documentation for the minor update. Please try again later”. (63158434)Workaround:
    1. Start up from macOS Recovery.
    2. If your data volume is encrypted, use Disk Utility to mount it.
    3. In Terminal type rm -rf "/Volumes/Macintosh HD - Data/private/var/folders/zz/zyxvpxvq6csfxvn_n00000y800007k".
    4. Restart your Mac.
  • You might need to adjust Energy Saver settings so your Mac doesn’t go to sleep while preparing to install macOS Big Sur 11 beta. (63166401)
  • APFS containers with non-default allocation block sizes aren’t currently supported for installation. (64312561)
  • Update iMac Pro to macOS High Sierra 10.13.6 or later before installing macOS Big Sur 11 beta. (64314272)
  • Installation might pause on Macs that don’t have input devices connected. (64348347)Workaround: Connect an input device and dismiss the alerts to continue installation.
  • You might be unable to install macOS Big Sur 11 beta onto additional volumes. (63677460, 64445236)Workaround: Create a bootable installer using the createinstallmedia command.
  • Software Update might unexpectedly indicate updates for your Mac are being managed by swscan.apple.com, instead of indicating your Mac is enrolled in the Apple Beta Software Program. This doesn’t impact your ability to update macOS Big Sur 11 beta. (64407436)
  • If macOS Big Sur 11 beta is installed into the same APFS container as previous versions of macOS, system software updates can no longer be installed on the previous versions of macOS. (64411484)
  • Installation on Core Storage Fusion volumes with FileVault encryption enabled isn’t currently supported. (64472080)


New Features
  • The kern.argmax limit has been increased, allowing programs to receive longer argument lists. (48661669)
  • Darwin kevent now allows non-parent processes to register for NOTE_EXITSTATUS, which delivers the same values as the wait() family of functions in the event data. Refer to the wait4() man page for more information. This event is subject to the following security checks:
    • The requesting process is allowed to send signals by sandbox restrictions.
    • The requesting process and the target process are running as the same user or the requesting process has root privileges. (58134463)
Known Issues
  • Installing a new kernel extension requires signing in as an Admin user. During kernel extension development, every time a kernel extension is changed, it must be signed and notarized. In both cases, your Mac must be restarted to load the extension. (55068348)
  • Remote panic dumps aren’t currently available. (57915324)
  • New in macOS Big Sur 11 beta, the system ships with a built-in dynamic linker cache of all system-provided libraries. As part of this change, copies of dynamic libraries are no longer present on the filesystem. Code that attempts to check for dynamic library presence by looking for a file at a path or enumerating a directory will fail. Instead, check for library presence by attempting to dlopen() the path, which will correctly check for the library in the cache. (62986286)
  • kmutil install might fail to build a development kextcache. (63772702)Workaround: Copy the release .elides to the locations of the development .elides: sudo cp /path/to/livemount/System/Library/KernelCollections/BootKernelExtensions.kc.elides /path/to/livemount/System/Library/KernelCollections/BootKernelExtensions.kc.development.elides sudo cp /path/to/livemount/System/Library/KernelCollections/BootKernelExtensions.kc.elides /path/to/livemount/System/Library/KernelCollections/BootKernelExtensions.kc.kasan.elides sudo cp /path/to/livemount/System/Library/KernelCollections/BootKernelExtensions.kc.elides /path/to/livemount/System/Library/KernelCollections/BootKernelExtensions.kc.debug.elides sudo cp /path/to/livemount/System/Library/KernelCollections/SystemKernelExtensions.kc.elides /path/to/livemount/System/Library/KernelCollections/SystemKernelExtensions.kc.development.elides sudo cp /path/to/livemount/System/Library/KernelCollections/SystemKernelExtensions.kc.elides /path/to/livemount/System/Library/KernelCollections/SystemKernelExtensions.kc.kasan.elides sudo cp /path/to/livemount/System/Library/KernelCollections/SystemKernelExtensions.kc.elides /path/to/livemount/System/Library/KernelCollections/SystemKernelExtensions.kc.debug.elides
  • Use only absolute paths with the --volume-root option of kmutil, and don’t use a trailing /. (63773848)
  • After removing a DriverKit extension, restart your Mac to complete uninstallation. (63995046)
  • Adhoc signed kernel extensions are displayed with a developer name of unknown in update dialogs and in Security preferences. (64215260)
  • Symbols exported by both xnu and Apple kernel extensions will change. Recompile your kernel extension with each update to macOS Big Sur 11 beta to ensure compatibility. (64262563)
  • Moving a kernel extension bundle out of /Library/Extensions might not completely uninstall it. (64331929)Workaround:
    1. Remove the extension from /Library/Extensions.
    2. Boot to macOS Recovery.
    3. Run Terminal.
    4. Enter the command kmutil invoke-panic-medic.
    5. Restart your Mac.
    6. Follow the prompt to open System Preferences and navigate to Security & Privacy.
    7. Follow the prompt to restart.
  • An unexpected System Extension Updated alert for third-party kernel extensions which are included in macOS might appear. These include: Accusys, Inc., ATTO Technology, Inc., Areca Technology Corporation, CalDigit, Inc., HighPoint Technologies, Inc., Promise Technology Mobile Apps, and Other World Computing. (64337113)
  • Kernel extensions using certain deprecated KPIs no longer load. Refer to the support page . While macOS Big Sur remains in development, you can temporarily disable System Integrity Protection to allow these deprecated extensions to load. (55068348)


Known Issues
  • Certain languages might exhibit clipped or misaligned layout. (63105445)
  • Certain languages might display unlocalized text. (63105674, 64040564, 64045718)
  • Some keyboard shortcuts might not work when running macOS Big Sur 11 beta in a language other than English. (63834383)


Known Issues
  • Widgets have access to location information even if the NSWidgetWantsLocation key isn’t in their Info.plist. (61953645)
  • In Swift, the authorizationStatus() property of CLLocationManager is incorrectly exposed as a method instead of a property. (62853845)


New Features
  • New APIs are available for using os_log from Swift as part of the os framework:
    • A new type Logger can be instantiated using a subsystem and category and provides methods for logging at different levels ( debug(_:) , error(_:) , fault(_:) ).
    • The Logger APIs support specifying most formatting and privacy options supported by legacy os_log APIs.
    • The new APIs provide significant performance improvements over the legacy APIs.
    • You can now pass Swift string interpolation to the os_log function.
    Note: The new APIs can’t be back deployed; however, the existing os_log API remains available for back deployment. (22539144)

Mac Catalyst

Known Issues
  • Content Extensions require a temporary workaround. (57442394)Workaround: Add the following key/value pair to the NSExtension dictionary in the Info.plist"NSExtensionContainingViewControllerClass" = "_UNNotificationContentExtensionViewController".
  • The new PHPickerViewController API currently produces unexpected results. (63631906)


Known Issues
  • If Messages is launched immediately after logging into iCloud, a login window might be displayed unexpectedly. (56309057)Workaround: Relaunch Messages after a few minutes or try restarting your Mac.
  • You might be unable to type in the photo picker search field when attaching a photo. (60011306)Workaround: Click the search field, press the tab key, then click the search field again.
  • You might receive an alert that indicates the maximum number of pinned conversations has been reached. (62919406)Workaround: Pin the conversation using drag and drop instead of using a swipe action or quick action with Haptic Touch.
  • Keyboard navigation to move focus between controls isn’t currently available. (63987810)
  • Messages Preferences are inaccessible until at least one message has been sent or received. (64122975)
  • Autocomplete fields and conversation titles aren’t visible while Messages is in full-screen mode. (64134303)
  • Message outlines might be missing when printing or exporting a conversation as a PDF. (64181169)
  • The first and last name fields in Messages Preferences might be misaligned. (64346872)Workaround: Set up your name in Messages Preferences by following the placeholder text then close and reopen Messages Preferences.


Known Issues
  • The logs property isn’t currently available from Swift while using Shader Validation. (64055248)

Migration Assistant

Known Issues
  • You might need to reset the password for a Standard account after migration, if the previous password doesn’t work. (63878129)Workaround: Log into an Admin account and change the Standard account’s password in the Users & Groups system preference.


Known Issues
  • Many elements of the user interface are currently missing when running Motion on macOS Big Sur 11 beta. (62531765)


Known Issues
  • Music might quit unexpectedly while using the search field. (64183834)


New Features
  • Experimental HTTP/3 support can be enabled in Safari via Experimental Features in the Developer menu, and enabled system-wide using the Terminal command defaults write -g CFNetworkHTTP3Override -int 3. (62969220)
Known Issues
  • HTTP/3 Draft 29 isn’t yet supported. (63524866)

Phone and FaceTime

Known Issues
  • Regular and emergency Wi-Fi calling using iPadOS 14 beta, macOS Big Sur 11 beta, and watchOS 7 beta isn’t currently available for T-Mobile USA customers. (63078572)


Known Issues
  • Importing Quartz or PDFKit frameworks in the macOS SDK might result in an errors such as “Umbrella for module ‘Quartz.PDFKit’ already covers this directory”. (63886438)

Safari and Webkit

New Features
  • Support for Web Extensions is now available. Existing Chrome and Firefox extensions can be converted for Safari using xcrun safari-web-extension-converter and distributed through the App Store for use in Safari 14. (55707949)
  • Webpage Translation is now available in the U.S. and Canada. Supported languages include English, Spanish, Simplified Chinese, French, German, Russian, and Brazilian Portuguese. Safari will automatically detect if translation is available based on your Preferred Languages list. (64437861)
Known Issues
  • Safari might quit unexpectedly when opening the Start Page if Frequently Visited Sites are visible as thumbnails. (63945984)Workaround: Make the window wider, hide the sidebar, or Control-click on Frequently Visited Sites and choose View as Icons.


New Features
  • macOS Big Sur 11 beta improves system security by requiring an administrator password when a certificate trust settings change is made in the admin trust domain. Running as the root user alone is no longer sufficient to modify certificate trust. User trust domain settings continue to require confirmation by entering the password for the user’s account. This change may affect you if one of the following is true:
    • You have written scripts which call /usr/bin/security add-trusted-cert -d ... as root.
    • Your process runs as root and calls the SecTrustSettingsSetTrustSettings function to trust a certificate.
  • Workflows that add trust settings in the admin trust domain, such as for an enterprise root certificate, may require modification if the user can’t authenticate as an administrator at the time settings are changed. (21855995)Workaround: Use Apple Configurator 2 to create and install a configuration profile containing your root certificate.


Known Issues
  • When quickly typing a search query in Spotlight, the result from a previous search might appear, then pressing return may create a wrong launch shortcut for subsequent queries. (64428836)Workaround: Type your query and click the desired result from the list that appears.
  • If you can’t find an application using Spotlight, launch the application at least once using Finder. (64463806)


Known Issues
  • Disclosure groups in Forms might produce unexpected results. (64079102)
  • Nested disclosure groups generated by OutlineGroup might produce unexpected results. (64097731)
  • The SceneStorage property wrapper isn’t yet supported. (64414712)
  • A label used with a symbol image might appear misaligned. (60193698)


Known Issues
  • Driver extensions might not launch on-demand after installation. (51229724)Workaround: Disable System Integrity Protection, then launch Terminal and execute the following command before approving the newly installed driver: sudo touch /Library/DriverExtensions.

Touch ID

Known Issues
  • Touch ID might become unexpectedly disabled on Macs with a T2 Security Chip after installing multiple operating systems. (62608379)Workaround: Reset the SMC of your Mac.


New Features
  • hv_vcpu_run_until(_:_:) now supports the deadline HV_DEADLINE_FOREVER . (57025216)
  • The new hv_vcpu_enable_managed_msr(_:_:_:) and hv_vcpu_set_msr_access(_:_:_:) enable direct MSR access from a guest. (50291076)
  • The function hv_vcpu_run(_:) is deprecated.


Known Issues
  • The NSSecureCoding implementation of VNRecognizedPointsObservation currently causes initWithCoder: to fail. (63681919)
  • The VNIdentifiedPointsObservation class is deprecated. Use VNRecognizedPointsObservation instances instead. (63690311)

Xcode Previews

Resolved Issues
  • Rebuilding against the iOS 14, macOS 11, watchOS 7, and tvOS 14 SDKs changes uses of GeometryReader to reliably top-leading align the views inside the GeometryReader . This was the previous behavior, except when it wasn’t possible to detect a single static view inside the GeometryReader . (59722992) (FB7597816)
About BjTechNews (1056 Articles)
An IT guy trying to learn everything about technology and sharing it with you all. I'm a blogger and video blogger who highlights daily news in the tech industry, promoting tips and hacks for fellow techies.

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