Xamarin.Mac 2.4

Xamarin.Mac 2.4

See the important license changes found in 2.4.2 related with Visual Studio Community Edition support.

The Xamarin.Mac 2.4 series is a continuation of the 2.3.x series of releases. It includes all of the releases of Cycle 6. It also includes a large number of new 10.11 APIs bindings.

The Xamarin.Mac 2.4 series upgrades the Mono stack from the Mono 4.0.xx series to the Mono 4.2.xx series. One of the major themes in Mono 4.2.xx series is the continued adoption of Microsoft's open sourced .NET code to improve the conformance, speed and memory usage of our stack.

Please note the API break on NSOutlineView noted in the Important Notes section.


El Capitan support for running and building applications.

Major improvements in our new project wizard and templates for Xamarin.Mac. We now have Storyboard support and Unified NSDocument based applications. See the Xamarin Studio release notes for additional details.

Improved OpenTK support under Unified Xamarin.Mac 4.5 profile. See caveat in Important Notes for a workaround in adding the actual reference.

Improvements in our binding and testing technology tracked down and fixed a significant number of ArgumentSemetics issues in our binding that could cause crashes.

Some new 10.10 APIs have bindings.

New Framework APIs

  • Contacts
  • CoreAudioKit
  • GameplayKit
  • Metal
  • MetalKit
  • ModelIO
  • SearchKit

Important Notes

Improvements in our registrar found a serious issue with NSOutlineViewDelegate ( 35356) that unfortuntly required an API break to fix. Any overrides of NSOutlineViewDelegate.ViewForTableColumn will need to be changed to NSOutlineViewDelegate.GetView.

Due to 35017 a handful of new APIs will crash with "System.ExecutionEngineException: SIGILL" when used. If you run into this, add --registrar=static to your additional mmp arguments to work around until fixed in Serivce Release 1.

Due to 30682 OpenTK.dll won't correctly show up in the reference list in Xamarin.Studio. You can browse to /Library/Frameworks/Xamarin.Mac.framework/Versions/Current/lib/mono/4.5/OpenTK.dll to add the reference for Unified projects targetting XM 4.5.

The new project template for Xamarin.Mac applications targetting 10.10 and later is storyboard based, however not all documentation has been updated yet. You can target 10.9 and before to get the older xib template.

The Xamarin.Mac F# templates on OS X 10.11 are broken due to 35851. A set of possible work arounds can be found here.

There have been a few additional minor API breaks to fix issues unfixable in other ways:

  • NSPasteboard CanReadObjectForClasses and ReadObjectsForClasses prototype was changed to be usable.
  • Many GetCompletions methods on AppKit classes have had their prototype changed to allow setting the index.
  • A few classes (NSUrlSessionUploadTask, GKAchievementViewController, GKLeaderboardViewController) had their base type changed to better reflect reality.
  • A number of CoreImage filters had breaking changes to fix major binding errors.

API Changes


Xamarin.Mac 2.4.2

This service release adds support for Visual Studio Community Edition

Also all editions may now make use of these features which were previously restricted:

  • Command-line builds, including headless builds
  • All types and assemblies may now be used, including System.Data.SqlClient
  • P/Invoke
  • No more application size limits

Finally it removes the splash screen which was shown at launch for applications built with the Trial edition.

Xamarin.Mac is a bugfix release.

Bug fixes

  • System.Configuration.ConfigurationErrorsException: Failed to load configuration section for dataContractSerializer when using ChannelFactory with the Xamarin.Mac .NET 4.5 Framework [ #36401 ]


XM is a compatibility release aligning with the rest of the Xamarin Platform for the new set of Stable builds. No XM specific fixes have been included as part of this release.

Xamarin.Mac is a bugfix release, fixing a number of reported issues, including regressions related to F# support with Xamarin.Mac.

Bug fixes

  • Mono cannot marshal a parameter that is a function pointer which takes a function pointer as a parameter [ #35545 ]
  • F# with Xamarin.Mac Broken on 10.11 [ #35851 ]

Xamarin.Mac is a bugfix release, fixing a number of reported issues. Issues related to F# will be fixed before this release arrives on stable.

Bug fixes

  • [XI/XM] Bug 34633 - Broken CGDataProvider causes crashes [ #34633 ]
  • MonoMac.Registrar.SharedStatic.IsNativeObject NotSupportedException at Mono.Cecil.TypeReference.Resolve [ #34609 ]
  • ObjCRuntime.Runtime.GetNSObject returns wrong object in [MonoPInvokeCallback]-attributed method on 64-bit devices when "Enable device-specific builds" is unchecked [#36317]
  • Build error with static registrar when exporting function/property that returns a Selector [ #34440 ]


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