Stable Release: Xamarin Studio 5.9.8, iOS 9.1 and OS X 10.11 upstream releases

BrendanZagaeskiBrendanZagaeski USForum Administrator, Xamarin Team Xamurai
edited November 2015 in Visual Studio

This is a combined bugfix and feature release:

  • Feature release to provide SDK bindings and IDE compatibility for iOS 9.1 and Xcode 7.1.
  • Bugfix release to address a few breakages caused by OS X 10.11 El Capitan.

If you find any new issues in this release compared to the previous Stable versions, please do file a quick bug report, and then feel free to add a note on this thread with the bug number. Thanks!

Previous versions, downgrading

You can downgrade back to the previous Stable version by manually reinstalling each old package. See the KB article on downgrading. If you have a Trial or Starter subscription (or simply would prefer an email with all the installer links you need), feel free to contact [email protected] to request the older versions.

Older Mono package versions are not currently listed on The Mono package for the previous Stable version is available here:

Release info




  • XamarinStudio- (cc5f6e5)

Release Blog:

Release notes:

Important notes

  • [iOS] Xamarin.iOS 9.1 (and XamarinVS 3.11.1585) now require Xcode 7 or higher, and consequently also OS X 10.10.5 or higher.

  • [iOS] Apple's release notes contain a list of changes and pending issues for both iOS 9.1 and Xcode 7.1.

  • [iOS] This version does not provide support for tvOS or watchOS in this release. Xamarin has previews (XI 9.3) available for both platforms. See the corresponding preview release thread for the latest information and download links.

Remaining issues on OS X 10.11 El Capitan

Bug 31369 - [Mono] Only affects Desktop Mono: programs that use the APIs in System.CodeDom.Compiler to compile code dynamically will fail with "System.SystemException: Error running mcs: Cannot find the specified file" or "System.SystemException: Error running vbnc: Cannot find the specified file".

New known issues

  • Bug 35320 - [iOS] [Xamarin Studio] "iPad Pro" is not listed in the simulators menu in Xamarin Studio. Possible temporary workaround: install the Xamarin Studio preview version from the Xamarin.iOS 9.3 preview thread. Keep in mind that this preview build has only been lightly tested. That said, it did allow successful building, deployment, and debugging on the "iPad Pro" simulator in brief informal tests using Xamarin.iOS 9.1.0.

  • Bug 35493 - [iOS] "Invalid WatchKit Support - The bundle contains an invalid implementation of WatchKit. The app may have been built or signed with non-compliant or pre-release tools." when attempting to submit a WatchKit (watchOS 1) app to the App Store. This issue is under active investigation for a fix. This issue does not affect Xamarin.iOS 9.0, so one possible temporary workaround is to downgrade Xcode to 7.0 and downgrade Xamarin.iOS to 9.0. Candidate fix for Xamarin Studio on Mac: See

  • Bug 34609 - [iOS] "Error MT4116: Could not register the assembly 'UnifiedSingleViewIphone1': System.NotSupportedException: Operation is not supported." when attempting to build apps for device that use IRPPreviewViewControllerDelegate or RPPreviewViewControllerDelegate. Workaround: Add Console.WriteLine (new NSSet<NSString> ()); anywhere in the application. This will prevent the NSSet<NSString> type from being linked away.

  • Non-public Bug 35445 - [iOS] [Xamarin Studio] Ignorable message "Error reading framework definition '/Library/Frameworks/Mono.framework/External/xbuild-frameworks/Xamarin.TVOS/v1.0'" when building iOS apps from the command line using mdtool with the -v verbosity flag. Possible workarounds: Remove the -v verbosity flag, or use xbuild to build from the command line rather than mdtool.

Remaining known issues from older release threads

The remaining known issues from older release threads ("Android M Support", "iOS 9 Support – Service Release 1", "Cycle 5 – Service Release 4", and earlier) are unchanged.

EDIT Oct 30: Mention Xamarin Studio preview build for the "iPad Pro" simulator.
EDIT Nov 02: Add WatchKit App Store submission Bug 35493, iOS Bug 35445, and iOS Bug 34609.
EDIT Nov 10: Add candidate fix for bug 35493 for XS on Mac.


  • MariuszHenkeMariuszHenke DEMember

    Is there a workaround for the iPad Pro bug?

  • BrendanZagaeskiBrendanZagaeski USForum Administrator, Xamarin Team Xamurai
    edited October 2015

    Is there a workaround for the iPad Pro bug?

    I am not aware of a direct workaround for the current Stable version of Xamarin Studio, but the "iPad Pro" simulator does appear correctly in the simulator list in the preview version of Xamarin Studio listed on the Xamarin.iOS 9.3 preview page:

    You can even use Xamarin Studio alongside the current Stable Xamarin.iOS This is an un-QA'd combination, but I have done some light local testing using these 2 versions myself, and I was able to build, deploy, and debug successfully on both simulator and device. So if you wish to use the "iPad Pro" simulator in Xamarin Studio you can try installing the preview version of Xamarin Studio without changing your current installed version of Xamarin.iOS.

  • CherubyxCherubyx CAUniversity ✭✭

    Jenkins cannot build iOS app without throwing an error about Xamarin.TVOS using Xamarin's Build Tool (mdtool).

    Bug 35445

This discussion has been closed.