Q:

Xamarin.Forms iOS mTouch Error

I am developing an application at ESRI ArcGIS Runtime (Xamarin.Forms [Shared]). I am using a default ArcGIS template in Visual Studio. When i run the app for IOS, it runs successfully but whenever i zoom in 4-5 times, the application returns me the error below and i added xamarin log file. I think it is not about Esri ArcGIS Runtime, it is about Xamarin iOS Touch. How can i fix that?
This errors in Visual Studio 2015 Output:
2017-02-23 14:43:37.330 UniversalApp1[19079:218799] 
Unhandled Exception:
System.NullReferenceException: Object reference not set to an instance of an object
  at System.Net.Http.NSUrlSessionHandler+NSUrlSessionHandlerDelegate.DidReceiveData (Foundation.NSUrlSession session, Foundation.NSUrlSessionDataTask dataTask, Foundation.NSData data) [0x00008] in /Users/builder/data/lanes/3985/35d1ccd0/source/xamarin-macios/src/Foundation/NSUrlSessionHandler.cs:267 
2017-02-23 14:43:37.337 UniversalApp1[19079:218799] Unhandled managed exception:
Object reference not set to an instance of an object (System.NullReferenceException)
  at System.Net.Http.NSUrlSessionHandler+NSUrlSessionHandlerDelegate.DidReceiveData (Foundation.NSUrlSession session, Foundation.NSUrlSessionDataTask dataTask, Foundation.NSData data) [0x00008] in /Users/builder/data/lanes/3985/35d1ccd0/source/xamarin-macios/src/Foundation/NSUrlSessionHandler.cs:267 
2017-02-23 14:43:37.338 UniversalApp1[19079:218799] critical: Stacktrace:

2017-02-23 14:43:37.338 UniversalApp1[19079:218799] critical: 
Native stacktrace:
2017-02-23 14:43:37.382 UniversalApp1[19079:218799] critical:   0   UniversalApp1                       0x0000000107b34dfd mono_handle_native_sigsegv + 253
2017-02-23 14:43:37.382 UniversalApp1[19079:218799] critical:   1   libsystem_platform.dylib            0x0000000111427bba _sigtramp + 26
2017-02-23 14:43:37.382 UniversalApp1[19079:218799] critical:   2   libsystem_kernel.dylib              0x00000001113eb430 libsystem_kernel.dylib + 1072
2017-02-23 14:43:37.383 UniversalApp1[19079:218799] critical:   3   libsystem_c.dylib                   0x000000011117efd7 abort + 129
2017-02-23 14:43:37.383 UniversalApp1[19079:218799] critical:   4   UniversalApp1                       0x0000000107ccc61f xamarin_unhandled_exception_handler + 47
2017-02-23 14:43:37.383 UniversalApp1[19079:218799] critical:   5   UniversalApp1                       0x0000000107b965fb mono_invoke_unhandled_exception_hook + 139
2017-02-23 14:43:37.383 UniversalApp1[19079:218799] critical:   6   UniversalApp1                       0x0000000107b3464f mono_handle_exception_internal + 5135
2017-02-23 14:43:37.384 UniversalApp1[19079:218799] critical:   7   UniversalApp1                       0x00000001
07b33238 mono_handle_exception + 24
2017-02-23 14:43:37.384 UniversalApp1[19079:218799] critical:   8   UniversalApp1                       0x0000000107aa9e0b altstack_handle_and_restore + 59
2017-02-23 14:43:37.384 UniversalApp1[19079:218799] critical:   9   ???                                 0x0000000121bac5b8 0x0 + 4860855736
2017-02-23 14:43:37.384 UniversalApp1[19079:218799] critical:   10  UniversalApp1                       0x0000000107b45387 mono_jit_runtime_invoke + 2247
2017-02-23 14:43:37.385 UniversalApp1[19079:218799] critical:   11  UniversalApp1                       0x0000000107bfa018 do_runtime_invoke + 88
2017-02-23 14:43:37.385 UniversalApp1[19079:218799] critical:   12  UniversalApp1                       0x0000000107bf9f90 mono_runtime_invoke + 208
2017-02-23 14:43:37.385 UniversalApp1[19079:218799] critical:   13  UniversalApp1                       0x0000000107cd15c5 xamarin_invoke_trampoline + 5589
2017-02-23 14:43:37.385 UniversalApp1[19079:218799] critical:   14  UniversalApp1             
          0x0000000107cd917d xamarin_arch_trampoline + 189
2017-02-23 14:43:37.386 UniversalApp1[19079:218799] critical:   15  UniversalApp1                       0x0000000107cda531 xamarin_x86_64_common_trampoline + 110
2017-02-23 14:43:37.386 UniversalApp1[19079:218799] critical:   16  CFNetwork                           0x000000010f9ec88c __67-[NSURLSession delegate_dataTask:didReceiveData:completionHandler:]_block_invoke.242 + 38
2017-02-23 14:43:37.386 UniversalApp1[19079:218799] critical:   17  Foundation                          0x00000001098149ad __NSBLOCKOPERATION_IS_CALLING_OUT_TO_A_BLOCK__ + 7
2017-02-23 14:43:37.386 UniversalApp1[19079:218799] critical:   18  Foundation                          0x000000010981468f -[NSBlockOperation main] + 101
2017-02-23 14:43:37.387 UniversalApp1[19079:218799] critical:   19  Foundation                          0x0000000109812d8c -[__NSOperationInternal _start:] + 672
2017-02-23 14:43:37.387 UniversalApp1[19079:218799] critical:   20  Foundation                        
  0x000000010980eccf __NSOQSchedule_f + 201
2017-02-23 14:43:37.387 UniversalApp1[19079:218799] critical:   21  libdispatch.dylib                   0x000000011108d12e _dispatch_client_callout + 8
2017-02-23 14:43:37.387 UniversalApp1[19079:218799] critical:   22  libdispatch.dylib                   0x00000001110724cf _dispatch_queue_serial_drain + 1018
2017-02-23 14:43:37.388 UniversalApp1[19079:218799] critical:   23  libdispatch.dylib                   0x0000000111072c9f _dispatch_queue_invoke + 1118
2017-02-23 14:43:37.388 UniversalApp1[19079:218799] critical:   24  libdispatch.dylib                   0x00000001110749dc _dispatch_root_queue_drain + 506
2017-02-23 14:43:37.388 UniversalApp1[19079:218799] critical:   25  libdispatch.dylib                   0x0000000111074782 _dispatch_worker_thread3 + 113
2017-02-23 14:43:37.388 UniversalApp1[19079:218799] critical:   26  libsystem_pthread.dylib             0x0000000111439712 _pthread_wqthread + 1299
2017-02-23 14:43:37.389 UniversalApp1[19079:218799] critical:   2
7  libsystem_pthread.dylib             0x00000001114391ed start_wqthread + 13
2017-02-23 14:43:37.389 UniversalApp1[19079:218799] critical: 
=================================================================
Got a SIGABRT while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries 
used by your application.
=================================================================
The app has been terminated.
Launch failed. The app 'UniversalApp1.iOS' could not be launched on 'iPhone SE iOS 10.2'. Error: An error occurred while executing MTouch. Please check the logs for more details.
The app has been terminated.

This part in Xamarin Logs
Xamarin.Messaging.Client.MessagingClient Error: 0 : [2017-02-23 14:43:39.9721] An error occured on the receiver while executing a post for topic xvs/idb/4.2.2.11/launch-app and client vs4120Sinan
Xamarin.Messaging.Exceptions.MessagingRemoteException: An error occured on client IDB42211 while executing a reply for topic xvs/idb/4.2.2.11/launch-app ---> Xamarin.Messaging.Exceptions.MonotouchException: An error occurred while executing MTouch
  at Xamarin.Messaging.IDB.MTouch+<RunAsync>d__8.MoveNext () [0x0024a] in <b3b99d4df65f4615ba6dd9add880a191>:0 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143 
  at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187 
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156 
  at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128 
  at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:535 
  at Xamarin.Messaging.IDB.MTouch+<RunAsync>d__7.MoveNext () [0x0007b] in <b3b99d4df65f4615ba6dd9add880a191>:0 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143 
  at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187 
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156 
  at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128 
  at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:535 
  at Xamarin.Messaging.IDB.MTouch+<LaunchAsync>d__5.MoveNext () [0x000bd] in <b3b99d4df65f4615ba6dd9add880a191>:0 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143 
  at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187 
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156 
  at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128 
  at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:535 
  at Xamarin.Messaging.IDB.Handlers.LaunchAppMessageHandler+<RunMTouchAsync>d__17.MoveNext () [0x00150] in <b3b99d4df65f4615ba6dd9add880a191>:0 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143 
  at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187 
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156 
  at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128 
  at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:535 
  at Xamarin.Messaging.IDB.Handlers.LaunchAppMessageHandler+<ExecuteOnSimulatorAsync>d__13.MoveNext () [0x00086] in <b3b99d4df65f4615ba6dd9add880a191>:0 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143 
  at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187 
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156 
  at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128 
  at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:535 
  at Xamarin.Messaging.IDB.Handlers.LaunchAppMessageHandler+<ExecuteAsync>d__12.MoveNext () [0x00092] in <b3b99d4df65f4615ba6dd9add880a191>:0 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143 
  at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187 
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156 
  at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128 
  at System.Runtime.CompilerServices.TaskAwaiter`1[TResult].GetResult () [0x00000] in <f712f98eb8e445c8918edaf595bbe465>:0 
  at Xamarin.Messaging.Client.RequestHandler`2+<HandleAsync>d__5[TMessage,TResult].MoveNext () [0x0011a] in <3ff57b845ff7490198f5f40dfdc63104>:0 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143 
  at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187 
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156 
  at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128 
  at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in <f712f98eb8e445c8918edaf595bbe465>:0 
  at Xamarin.Messaging.Client.MessageHandlerManager+<>c__DisplayClass17_0`2+<<RegisterHandlerAsync>b__1>d[TMessage,TResult].MoveNext () [0x000b3] in <3ff57b845ff7490198f5f40dfdc63104>:0 
--- End of stack trace from previous location where exception was thrown ---
  at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw () [0x0000c] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/exceptionservices/exceptionservicescommon.cs:143 
  at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Threading.Tasks.Task task) [0x00047] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:187 
  at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Threading.Tasks.Task task) [0x0002e] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:156 
  at System.Runtime.CompilerServices.TaskAwaiter.ValidateEnd (System.Threading.Tasks.Task task) [0x0000b] in /private/tmp/source-mono-4.8.0/bockbuild-mono-4.8.0-branch/profiles/mono-mac-xamarin/build-root/mono-x86/mcs/class/referencesource/mscorlib/system/runtime/compilerservices/TaskAwaiter.cs:128 
  at System.Runtime.CompilerServices.ConfiguredTaskAwaitable`1+ConfiguredTaskAwaiter[TResult].GetResult () [0x00000] in <f712f98eb8e445c8918edaf595bbe465>:0 
  at Xamarin.Messaging.Client.MessagingClient+<ReplyAsync>d__34`2[TRequest,TResponse].MoveNext () [0x000cf] in <3ff57b845ff7490198f5f40dfdc63104>:0 
   --- End of inner exception stack trace ---
   at Xamarin.Messaging.Client.MessagingClient.<PostAsync>d__23`2.MoveNext()

Visual Studio 2015 Community ( Version: 14.0.25431.01 Update 3 )
Xamarin 4.2.0 ( Xamarin.Android 7.0 – Xamarin.iOS 10.2 )
ArcGIS Runtime 100 .Net SDK

Thanks in advance,
Sinan

A:

This error is due to a change in behavior at Xamarin's Cycle 9 release.  We have logged the issue with Xamarin (see here).  Until the underlying problem is resolve, it can be avoided by remaining on or downgrading to the most recent Cycle 8 release.
Edit - This problem was fixed in Xamarin's Xcode 8.3 update to the Cycle 9, SR0 release (i.e. Xamarin iOS 10.6). It is also fixed in Xamarin's latest release (15.1). 
-Rich
ArcGIS Runtime Team

