Xamarin.iOS 12.8 Release Notes

System Requirements | What's New | Known Issues | Blogs | Open Source

To see installation instructions for both Visual Studio for Mac and Visual Studio 2019, please visit http://releases.xamarin.com/


  • The latest features and APIs requires Xcode 10.2 and the bundled iOS, tvOS and watchOS SDKs
  • Apple Xcode 10.2 requires a Mac running OSX 10.14.3 (Mojave) or newer

What's New in this Release

Support for Xcode 10.2

For more information you can consult the Xcode 10.2 release notes from Apple.

Support for iOS 12.2

For more information you can consult the iOS 12.2 release notes from Apple.

Support for tvOS 12.2

For more information you can consult the tvOS 12.2 release notes from Apple.

Support for watchOS 5.2

For more information you can consult the watchOS 5.2 release notes from Apple.

Release History

This version of Xamarin.iOS corresponds to our 16.0 (d16-0) milestone and includes support for Xcode 10.2.

  • May 2, 2019 - Xamarin.iOS
  • April 4, 2019 - Xamarin.iOS

You can learn more about how we ship our releases in the Visual Studio 2019 Release Rhythm document.

May 2, 2019 - Xamarin.iOS

Issues Fixed

  • 5132 - [uikit] Don't crash if UIGestureRecognizer.Dispose is called multiple‚Ķ times
  • 5798 - [mono] Fixed LLVM optimization regression where APIs that would return generics might sometimes not work properly

April 4, 2019 - Xamarin.iOS

This release is based on Xamarin.iOS 12.6 (d16-0) and the Xcode 10.2 final release.

Known Issues

64 bits watchOS support

  • Xcode 10 GM added support for 64 bits watch application, aka arm64_32. The current app store submission process requires this architecture to be included in your application when including watch support. You can workaround this with [https://github.com/xamarin/xamarin-macios/issues/4810#issuecomment-421338365](these instructions).

  • Trying to run a watch app on the new Series 4 Apple Watch will fail with this error:

    IncorrectArchitecture: Failed to find matching arch for 32-bit Mach-O input file ...
    error MT1006: Could not install the application 'MyTestApp.app' on the device 'MyDevice': AMDeviceSecureInstallApplicationBundle returned: 0xe8000087 (kAMDIncorrectArchitectureError).

    This is because the S4 device can only execute native arm64_32 code, not armv7k like previous watches.

    Please read https://github.com/xamarin/xamarin-macios/issues/4864 for more information and a workaround.

Using an older Xcode version

Using an older Xcode version (than the one mentioned in the above requirements) is often possible. For more information see the following documentation.

API Diff

The following documents contains a complete list of the API changes since the Xamarin.iOS 12.6 stable release:

Integrated Mono Features/Fixes

Xamarin.iOS uses a customized runtime and base class libraries (BCL) from Mono 5.18 Commit 163f45d8


Your feedback is important to us. If there are any problems with this release, check the Xamarin.iOS Forums and Xamarin Mac/iOS Github Repository for existing issues. If you do not find any matching issue, please feel free to start a new discussion and report an issue.

Open Source

Xamarin.iOS is based on the following open-source repositories: