This thread has now been closed to direct all further updates about this release onto the corresponding Stable release announcement:

http://forums.xamarin.com/discussion/56942/stable-release-xamarin-4-cycle-6-service-release-0/p1

Release Blog post: https://releases.xamarin.com/alpha-preview-cycle-6-service-release-0

This is a small bugfix release. It addresses a first handful of the more severe or commonly reported issues from the Xamarin 4, Cycle 6 Feature Release. See the Release Blog post for details.

Remaining known issues

An additional Service Release is tentatively planned for Alpha release within the next few weeks. It will include fixes for several other regressions introduced by the Cycle 6 Feature Release.

As mentioned on the Release Blog post, there is one especially widely reported regression for which a fix is not yet included in the Alpha version of Cycle 6 Service Release 0. This issue is under active investigation for a possible fix in a later build of Service Release 0:

• [Xamarin.VS (36185)] – Hang (GUI lockup, freeze) when opening or working on a solution that contains an Android project. Known temporary workaround: delete the hidden .suo file or .vs folder in the solution directory.

Bug filing

If you find any new issues in this release compared to the current Stable versions or the previous "Xamarin 3" versions that you would like the Xamarin team to investigate, please do file a quick bug report, and then feel free to add a note on this thread with the bug number. Thanks!

• File a bug using the "Cycle 6" ("C6") new bug form here: https://bugzilla.xamarin.com/newbug?release=C6.

New known issues

To save time be sure to check the lists of known issues in the release notes (linked below) before filing a bug.

You can view the complete list of new bug reports against the Xamarin 4 ("Cycle 6") Stable versions, excluding the issues fixed in Service Release 0 using the following Bugzilla query:

• Xamarin 4 "Cycle 6" Bug List, excluding issues now fixed in Service Release 0

  This list only includes bugs for which a fix has not yet been released as of "Service Release 0." Fixes for issues on this list already marked "FIXED" have not yet been released, but will be included in a future Service Release.

Previous versions, downgrading

You can install this new Alpha version or switch back to the current Stable version by changing updater channels.

Older versions

You can downgrade back to the previous Xamarin 3 Stable versions by manually reinstalling each old package. See the "Get the latest stable version of Xamarin 3" section on your account page: https://store.xamarin.com/account/my/subscription/downloads#xamarin3. If you have any trouble downloading the previous versions from that link, would like to install an older set of versions, or simply would prefer an email with all the installer links you need, feel free to contact [email protected].

Release info

Windows

• Xamarin.VisualStudio_4.0.0.1694.msi (b535f47) Release Notes

Mac

• XamarinStudio-5.10.1.1.dmg (bee8b40) (This is an update for Mac only) Release Notes
• monotouch-9.2.1.52.pkg (d070a7b) Release Notes

Release Blog post: https://releases.xamarin.com/alpha-preview-cycle-6-service-release-0

See the first entry in the release blog and "Xamarin Release Cycles" for more information about "cycles," "service releases," and "feature based releases."

Compatibility notes

(These are the same as for the initial Cycle 6 Feature Release.)

• [XamarinVS] The Cycle 6 builds of XamarinVS now require Visual Studio 2012 or higher. Following along with the end of Mainstream Support for Visual Studio 2010 by Microsoft, Cycle 6 is not compatible with VS 2010.

• [iOS] The Cycle 6 builds now require Xcode 7 or higher. For example, attempting to build an iOS app for device using Xcode 6.4 will now fail with "Native linking failed, undefined symbol: ___divdc3".

• [Xamarin Studio] [XamarinVS] [iOS] [Android] [Xamarin.Mac] Support for OS X 10.9 Mavericks has been deprecated. The Cycle 6 builds now require OS X 10.10 Yosemite.

EDIT Nov 30: Make a small formatting change.