Stable service release: Xamarin Studio 5.9.2, bug fixes for 5.9.0

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

Released versions:


  • XamarinStudio- (288eb01)
  • XamarinStudio- (5a524e1) (Hotfix)


  • XamarinStudio- (288eb01)
  • XamarinStudio- (5a524e1) (Hotfix)
  • monotouch- (e6ebd18)
  • monotouch- (6916d0e) (Hotfix)
  • MonoFramework-MDK- (ed1d3ec)
  • mono-android-5.1.2-1.pkg (4ab8d98)
  • mono-android-5.1.3-1.pkg (d419c93) (Hotfix)
  • xamarin.mac- (e6ebd18)

Reason for release: Bug fixes for the Stable Channel release on April 29.

Release notes:

Date published:

Previous versions, downgrading

You can downgrade back to the previous Stable versions (from April 29) by manually reinstalling each old package (see also the article about downgrading). The links to the previous Stable versions are:



Older versions (from before April 29)

If needed, you can also downgrade back to the older versions (from before April 29) by manually reinstalling each old package. See the "Previous versions, downgrading" section on the previous Stable release thread for the older downgrade links.

Guidelines for this thread

  1. This first post will be updated regularly.

  2. Hopefully this thread will help answer "what might break if I update to this release?"

  3. If you find a new problem that is specific to this version, please file a bug report (if this link redirects to the top-level page the first time you click it, try clicking it once more).

  4. Please discuss older bugs that are unchanged in this release compared to the previous Stable version in Bugzilla instead.

  5. Of course for questions and discussions about topics other than bugs, feel free start new forum threads.

Remaining known issues from the April 29 Stable Channel release, with more common or severe issues near the top

(Candidate fixes for many of these remaining issues are now available on the Alpha updater channel.)

  • Bug 28961 - [iOS] "error MT3001: Could not AOT the assembly", "error: invalid symbol redefinition". (This can also appear as "System.ArgumentOutOfRangeException: startIndex > this.length" in the "Output -> Xamarin Log" in VS.) One common cause of this error is the use of [MethodImplAttribute(MethodImplOptions.Synchronized)]. Now fixed in the Beta and Alpha channels. (Old workaround for projects that use [MethodImplAttribute(MethodImplOptions.Synchronized)]: remove [MethodImplAttribute(MethodImplOptions.Synchronized)] and manually synchronize the methods using lock statements instead (

  • Non-public Bug 28995 - [Android] On certain devices, certain apps crash frequently due to "System.ExecutionEngineException: SIGILL". Now fixed in the Beta and Alpha channels.

  • Bug 30318 - [Android] Windows only: Breakpoints in PCL projects do not work after cleaning solution, redeploying, and restarting debugging. Now fixed in the Beta and Alpha channels. (Old partial workaround: delete all the bin folders in the solution after cleaning.)

  • Non-public Bug 30057 - [Android] Windows only: the debugger will not be able resolve breakpoints unless "Shared Runtime" is ON and the Linker is OFF (under "Project Properties -> Android Options" in Visual Studio or "Project Options -> Android Build" in Xamarin Studio). Now fixed in the Beta and Alpha channels.

  • Bug 29326 - [Android] String resources defined in NuGet packages overwrite string resources defined in app project, causing the displayed app name to be incorrect for example. Workaround: avoid using the same string key that is used in the NuGet packages.

  • Bug 29211 - [iOS] Enabling the linker when the solution includes a PCL that uses System.IO.Compression causes "Could not load file or assembly 'System.IO.Compression' or one of its dependencies" at run time. The same problem can also happen with System.Threading.Tasks (and probably also several other assemblies). Now fixed in the Beta and Alpha channels. (Old workaround: add -linkskip=System.IO.Compression (or -linkskip=System.Threading.Tasks for System.Threading.Tasks) under "project options -> iOS Build -> Additional mtouch arguments".)

  • Non-public Bug 30481, Bug 29557 - [Mono] [Android] [iOS] SqlConnection.GetSchema() fails with "SourceTable is required to be a non-empty string".

  • Bug 30548 - [Android] Under certain conditions new threads take several seconds to start. This problem seems to be triggered by Xamarin.Insights 1.10. Partial workarounds: upgrade Xamarin.Insights to version 1.10.3, downgrade it to version 1.9, or remove it entirely.

  • Bug 30420 - [iOS] DequeueReusableCell(cellIdentifier) returns null if this.TableView is called in the TableView constructor. Workaround: perform all initialization operations for the TableView in the ViewDidLoad() or ViewWillAppear() methods rather than the constructor.

  • Bug 30072 - [Xamarin Studio] [Android] Xamarin Studio sometimes crashes with SIGABRT in gtk_text_view_validate_onscreen() after password is entered during "Import an Existing Key" in "Build -> Archive for Publishing -> Sign and Distribute" workflow. Now fixed in the Beta and Alpha channels.

  • Bug 29745 - [iOS] Error due to duplicate symbols during native compilation for device: "duplicate symbol _monoeg_g_array_new" (and many similar messages). Workarounds: disable profiling under "Project Properties -> iOS Build", or if your app uses the -all_load linker flag (via either gcc_flags or LinkerFlags) try removing it.

  • Non-public Bug 29538 - [Android] Profiling via the graphical Xamarin Profiler ("Run -> Start Profiling") causes the app to crash at startup. Now fixed in the Beta and Alpha channels.

  • Bug 28808 - [Xamarin Studio] Uncommon "Too many open files" error, possibly related to keeping a solution open in Xamarin Studio across several sleep/wake cycles, leads to an inability to save the solution, and consequently a loss of the solution file contents.

  • Bug 29001 - [Xamarin Studio] Under certain conditions, clicking in the universal search bar can trap the cursor focus, preventing text entry into the text editor window.

  • Bug 30915 - [Xamarin Studio] [Android] Xamarin Studio repeatedly asks for the password for the selected certificate when attempting to sign using SHA1withDSA certificates from keystore files. Xamarin Studio should instead display the error message from jarsigner: "private key algorithm is not compatible with signature algorithm" as it did in Xamarin Studio 5.8. (SHA1withRSA or MD5withRSA certificates do work without error.)

  • Bug 29731 - [Android] Android.Bluetooth.BluetoothAdapter.Enable is incorrectly marked as [Obsolete("deprecated")] for API level 20 and higher.

  • Non-public Bug 29725 - [Xamarin Studio] [iOS] [Android] Expressions in the Watch window are cleared each time you stop debugging. Now fixed in the Beta and Alpha channels.

  • [Xamarin Studio] Xamarin Studio 5.9 for Mac requires OS X 10.9 or higher. The updater does not currently block this update on OS X 10.8. The behavior of the updater for this kind of version incompatibility will be improved in the future.

New known issues

  • Bug 30488, Bug 31208, and several other related bugs - [iOS] "error MT3001: Could not AOT the assembly" and "Error setting up ... class vtable". This problem is caused by a new error check that was added in Xamarin.iOS 8.10.1. It will be restored to the old 8.10.0 behavior in the next Beta release (tentatively on June 24).

EDIT June 3: Update version numbers for Android M Preview SDK hotfix. Add Mono Bug 30481.
EDIT June 4: Adjust wording about downgrading to "older versions."
EDIT June 10: Mark bugs that are now fixed in the Alpha channel "Service Release 2" (28961 28995 30371 29211 30072 29538 29849 29725)
EDIT June 11: Correction: the fixes for 30318 and 30057 will be in the next Alpha build, which should be available in less than 1 week.
EDIT June 23: Mark additional bugs that are now fixed in the Beta channel "Service Release 2" (30318 30057 30420). Add XS Android bug 30915. Add iOS bug 30488.
EDIT June 24: Update version numbers for iOS 9 Preview critical compatibility hotfix.


  • DarrelDarrel USMember

    Could someone confirm that the C# 6.0 language support hasn't been implemented in "source analysis" in Xamarin Studio? Using the new syntax compiles but the IDE shows a lot of errors that should have been proper syntax. Thanks.

  • DavidDancyDavidDancy AUMember ✭✭✭✭

    Is anything planned to address the startup times for an iOS app? I'm compiling using the latest XS Alpha, and startup times on the app I'm making are such that after most code changes it takes 3 or sometimes 4 Run commands to get the app going.
    My computer is a spinning-disk laptop from 2011 so I suspect that upgrading to a SSD will ease the problem, but still, it's worrying that it takes so long for the app to start that the Watchdog ends up killing it before it can get going. I'm of course aware that iOS devices don't have spinning disks, so the app may well not suffer too badly when I run it on an actual device, but it's very much not a delightful experience when I'm developing against the iOS simulator.
    I observe that some caching of stuff appears to occur on each run, and the bootstrap process appears to get further along with that caching on each start - hence the 3 or 4 restarts required to actually get the app to run.
    I observe also that this issue comes and goes with different versions of XS. About 2 versions ago (sorry I forgot to record which one it was) the issue almost went away completely; with this latest version it's worse than it has ever been.
    When I compare the startup times of an Objective-C app vs a C# app on iOS, especially if the C# app has lots of third-party DLLs included, it's quite a stark contrast.
    Is there anything I can do in my app to help the situation? Are there any third-party DLLs that make the problem worse? Literally all the app does on startup is fill in its DI container, create the App subclass, and set the MainPage. Everything else happens from there, but getting to that point takes so long...

  • JooAlmeida.9370JooAlmeida.9370 PTMember
    edited June 2015

    Breakpoints are not hitting when I updated... How can I downgrade ? I'm feeling kinda desperated

    EDIT: Downgraded version problem stills exits..

  • BrendanZagaeskiBrendanZagaeski USForum Administrator, Xamarin Team Xamurai

    Breakpoints are not hitting when I updated

    @JooAlmeida.2533, correct. As stated in the first post in the thread, Bug 30318 is still a "remaining known issue" from the April 29 release. In order to avoid that problem completely, you'll need to downgrade to the versions from before April 29. The first post in the thread includes instructions for how to find those older versions.

    Bug 30318 - [Android] Windows only: Breakpoints in PCL projects do not work after cleaning solution, redeploying, and restarting debugging. Partial workaround: delete all the bin folders in the solution after cleaning.

  • QuorralyneQuorralyne USMember ✭✭

    @BrendanZagaeski do I really have to downgrade PLUS follow the partial workaround for hitting my Android breakpoint? I can't get either to work.

  • JooAlmeida.9370JooAlmeida.9370 PTMember

    @BrendanZagaeski I managed to get it working , finnaly!
    Using 5.9 ( build 431 ).

  • BrendanZagaeskiBrendanZagaeski USForum Administrator, Xamarin Team Xamurai

    Quorralyne, either downgrading or using the partial workaround should have a similar effect. See:

    ... on the corresponding Xamarin.Android release thread for some additional context and more things to check.

This discussion has been closed.