iOS 11.1 SDK Release Notes



iOS 11.1 SDK provides support for developing iOS apps. It’s packaged with a complete set of Xcode tools, compilers, and frameworks for creating apps for iOS, watchOS, tvOS, and macOS. These tools include the Xcode IDE and the Instruments analysis tool, among many others.

With this software you can develop apps for iPhone, iPad, or iPod touch running iOS 11.1. You can also test your apps using the included Simulator, which supports iOS 11.1. iOS 11.1 SDK requires a Mac computer running macOS Sierra 10.12.6 or later.

This version of iOS is intended for installation only on devices registered with the Apple Developer Program. Attempting to install this version of iOS in an unauthorized manner could put your device in an unusable state.

Tools and Developer Resources

You obtain Xcode 9.1 from the Mac App Store. It is a free download that installs directly into the Applications folder.

The Apple Developer Program provides everything you need to build and distribute your apps on the App Store for iPhone, iPad, Mac, and Apple Watch. Membership includes access to beta OS releases, advanced app capabilities, and tools to develop, test, and distribute apps and Safari extensions. For more information, visit Apple Developer Program.

Apple provides the following resources to support your development:

Bug Reporting

For issues not mentioned in Notes and Known Issues, please file bugs through the Apple Developer website

When filing a bug, please include the full version number in the bug title and in the description. To find the version number, open Settings > General > About. The version number is shown next to Version and looks like 11.1 (15Bxxx).

Additionally, you may discuss these issues and iOS 11 SDK in the Apple Developer Forums: To get more information about iCloud for Developers, go to

Release Notes Updates

iOS Release Notes is sometimes updated after a release is distributed. You can check for the most up-to-date version of iOS Release Notes at the Apple Developer website by checking

Revision: iOS1110 - IRN1

Notes and Known Issues

The following items relate to using iOS 11 SDK to develop code.


Known Issues

  • Continuing from a breakpoint while debugging an ARSession may result in VIO breaking. Any visual objects placed in the world/anchor are not visible. (31561202)


Known Issues

  • When using the TrueDepth front-facing camera on iPhone X, setting the capture device’s activeFormat to a binned video format (see isVideoBinned) for capture and enabling delivery of camera calibration data causes the resulting AVCameraCalibrationData to contain invalid information for the intrinsicMatrix property. (34200225)

    Workaround: Select an alternate capture format whose isVideoBinned property is false.


Known Issues

  • Initializing an EKCalendarChooser from EventKit can result in an app crash. (34608102)

  • Storing data to a nondefault event store in EventKit may not work. (31335830)

Files App (Simulator)

Known Issues

  • In Simulator, documents saved in Local Storage won't load again through the Document Browser. (32509670)


Known Issues

  • Clients of NSURLSessionStreamTask that use a non-secure connection fail to connect when an error occurs during PAC file evaluation and the system is configured for either Web Proxy Auto Discovery (WPAD) or Proxy Automatic Configuration (PAC). A PAC evaluation failure can occur when the PAC file contains invalid JavaScript or the HTTP host serving the PAC file is unreachable. (33609198)

    Workaround: Use startSecureConnection() to establish a secure connection.

Replay Kit

Known Issues


Known Issues

  • VNFaceLandmarkRegion2D is currently unavailable in Swift. (33191123)

  • Facial landmarks identified by the Vision framework may flicker in temporal use cases such as video. (32406440)


Known Issues

  • Debugging a disabled Messages extension may cause the Messages app to crash. (33657938)

    Workaround: Enable the extension before starting the debug session.

  • After a simulated iOS device starts up, it’s not possible to pull down the Notification center. (33274699)

    Workaround: Lock and unlock the simulated device and then reopen Home screen.