Stable service release: Xamarin.iOS 8.10.1, bug fixes for 8.10.0

BrendanZagaeskiBrendanZagaeski USForum Administrator, Xamarin Team Xamurai
edited June 2015 in Xamarin.iOS

Released versions:


  • Xamarin.VisualStudio_3.11.586.msi (a91e30d)
  • Xamarin.VisualStudio_3.11.590.msi (5160db7) (Hotfix)


  • monotouch- (e6ebd18)
  • monotouch- (6916d0e) (Hotfix)
  • MonoFramework-MDK- (ed1d3ec)

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 30059 - [XamarinVS] [iOS] "Mono.Debugger.Soft.CommandException: Debuggee returned error code 200." when hitting breakpoints in PCLs in certain projects when running XamarinVS on certain computers.

  • 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 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 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.

  • Bug 29849 - [XamarinVS] [iOS] The "Visual C# -> Mobile Apps -> Blank App (Xamarin.Forms Portable)" template includes an iOS project that has a non-empty value for the <CodesignEntitlements> property for the iPhoneSimulator configurations, meaning that the iPhoneSimulator configuration will attempt to perform code signing. This is inconsistent with the other templates and also with the corresponding Xamarin Studio template on Mac. Workaround: open the .csproj file in a text editor and delete the <CodesignEntitlements> property from all of the iPhoneSimulator configurations. The template project is now fixed in the Beta and Alpha channels.

  • 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.

Remaining known issues from before the April 29 Stable Channel release

(For issues that might behave differently for some customers after updating to this new release, or that might be difficult to find via Bugzilla.)

  • Bug 28027 - [XamarinVS] [iOS] The debugger sometimes fails to connect properly after the app launches. This means breakpoints will not be hit during that launch of the app and the "Output -> Debug" window will be blank. Repeating the steps of (a) stopping the debugger and (b) relaunching the app will eventually lead to a successful connection. This problem has existed since at least XamarinVS 3.9.483, but some recent reports suggest that it has become more common for certain users in this latest release. To make a reasonable guess, the problem might be caused by a race condition. Based on that guess, this new version might have changed some timings and increased the probability of hitting the issue on a wider range of system configurations. The bug is under active investigation.

  • Bug 29897 - [XamarinVS] [iOS] Breakpoints sometimes don't work when debugging on iOS device. Based on the observed behavior of this problem, it appears to have the same underlying cause as Bug 28027.

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 iOS bug 30488.
EDIT June 24: Update version numbers for iOS 9 Preview critical compatibility hotfix.

This discussion has been closed.