title: EXC_BAD_ACCESS KERN_INVALID_ADDRESS 0x0000000000000000 : Xamarin Forms, iOS, intermittent Crash
body: <ul>
  <li>Xamarin Forms Version : 4.8.0.1560</li>
  <li>Happens for multiple iOS versions</li>
  <li>iPhone &amp; iPad</li>
  </ul>
  <p>Crash is intermittent &amp; happens in production release for 12 % of overall users.</p>
  <p>firebase crash analytics shows below line as a crashing point &amp; the list is never null or empty</p>
  <pre><code> try { foreach (var item in ViewModel?.availableList?.anotherList?.GetRange(0, 2)) } catch (Exception ex) { do something}
  </code></pre>
  <p><strong>Do you guys think that deep copying it &amp; then iterating will help?</strong></p>
  <p>Note :</p>
  <ul>
  <li>I am unable to reproduce it myself yet.</li>
  <li>I have also verified that list is not getting updated from any other threads</li>
  </ul>
  <p>Complete log</p>
  <pre><code> Crashed: tid_407
  0  someNameSpace.iOS                     0x1047ac840 someNameSpace._Views_view._Addpocket + 386 (view..xaml.cs:386)
  1  someNameSpace.iOS                     0x1047ab204 someNameSpace._Views_view._Displaypocket + 174 (view..xaml.cs:174)
  2  someNameSpace.iOS                     0x1047ab204 someNameSpace._Views_view._Displaypocket + 174 (view..xaml.cs:174)
  3  someNameSpace.iOS                     0x1047e2c08 someNameSpace._Views_view.___ctorb__9_5_string + 57 (view..xaml.cs:57)
  4  someNameSpace.iOS                     0x103538880 wrapper_runtime_invoke_object_runtime_invoke_dynamic_intptr_intptr_intptr_intptr + 4342433920
  5  someNameSpace.iOS                     0x10558b21c mono_jit_runtime_invoke + 3165 (mini-runtime.c:3165)
  6  someNameSpace.iOS                     0x105646940 mono_runtime_invoke_checked + 3052 (object.c:3052)
  7  someNameSpace.iOS                     0x10564e214 mono_runtime_try_invoke_array + 5626 (object.c:5626)
  8  someNameSpace.iOS                     0x1055efcec ves_icall_InternalInvoke + 3927 (icall.c:3927)
  9  someNameSpace.iOS                     0x105600f50 ves_icall_InternalInvoke_raw + 667 (icall-def.h:667)
  10 someNameSpace.iOS                     0x103301808 wrapper_managed_to_native_System_Reflection_RuntimeMethodInfo_InternalInvoke_System_Reflection_RuntimeMethodInfo_object_object___System_Exception_ + 4340111368
  11 someNameSpace.iOS                     0x1033019b0 System_Reflection_RuntimeMethodInfo_Invoke_object_System_Reflection_BindingFlags_System_Reflection_Binder_object___System_Globalization_CultureInfo + 4340111792
  12 someNameSpace.iOS                     0x1032ef48c System_Reflection_MethodBase_Invoke_object_object__ + 4340036748
  13 someNameSpace.iOS                     0x10369259c Xamarin_Forms_MessagingCenter_Subscription_InvokeCallback_object_object + 95 (MessagingCenter.cs:95)
  14 someNameSpace.iOS                     0x103691974 Xamarin_Forms_MessagingCenter_InnerSend_string_System_Type_System_Type_object_object + 213 (MessagingCenter.cs:213)
  15 someNameSpace.iOS                     0x1036910d4 Xamarin_Forms_MessagingCenter_Xamarin_Forms_IMessagingCenter_Send_TSender_REF_TSender_REF_string + 128 (MessagingCenter.cs:128)
  16 someNameSpace.iOS                     0x103691078 Xamarin_Forms_MessagingCenter_Send_TSender_REF_TSender_REF_string + 121 (MessagingCenter.cs:121)
  17 someNameSpace.iOS                     0x1045837e0 someNameSpace._ViewModels_view.Model__GetpocketInfod__23_MoveNext + 177 (view.Model.cs:177)
  18 someNameSpace.iOS                     0x1032df31c System_Runtime_CompilerServices_AsyncMethodBuilderCore_MoveNextRunner_InvokeMoveNext_object + 4339970844
  19 someNameSpace.iOS                     0x10325f8fc System_Threading_ExecutionContext_RunInternal_System_Threading_ExecutionContext_System_Threading_ContextCallback_object_bool + 4339448060
  20 someNameSpace.iOS                     0x10325f6fc System_Threading_ExecutionContext_Run_System_Threading_ExecutionContext_System_Threading_ContextCallback_object_bool + 4339447548
  21 someNameSpace.iOS                     0x1032df1d8 System_Runtime_CompilerServices_AsyncMethodBuilderCore_MoveNextRunner_Run + 4339970520
  22 someNameSpace.iOS                     0x10327f264 System_Threading_Tasks_AwaitTaskContinuation_InvokeAction_object + 4339577444
  23 someNameSpace.iOS                     0x10327f394 System_Threading_Tasks_AwaitTaskContinuation_RunCallback_System_Threading_ContextCallback_object_System_Threading_Tasks_Task_ + 4339577748
  24 someNameSpace.iOS                     0x10327e5ac System_Threading_Tasks_SynchronizationContextAwaitTaskContinuation_Run_System_Threading_Tasks_Task_bool + 4339574188
  25 someNameSpace.iOS                     0x103278740 System_Threading_Tasks_Task_FinishContinuations + 4339550016
  26 someNameSpace.iOS                     0x103276b90 System_Threading_Tasks_Task_FinishStageThree + 4339542928
  27 someNameSpace.iOS                     0x103271ab4 System_Threading_Tasks_Task_1_TResult_REF_TrySetResult_TResult_REF + 4339522228
  28 someNameSpace.iOS                     0x1032dd98c System_Runtime_CompilerServices_AsyncTaskMethodBuilder_1_TResult_REF_SetResult_TResult_REF + 4339964300
  29 someNameSpace.iOS                     0x1045cbcf8 someNameSpace._Repo_FoodieClubRepo__Getpocketd__18_MoveNext + 126 (FoodieClubRepo.cs:126)
  30 someNameSpace.iOS                     0x1032df31c System_Runtime_CompilerServices_AsyncMethodBuilderCore_MoveNextRunner_InvokeMoveNext_object + 4339970844
  31 someNameSpace.iOS                     0x10325f8fc System_Threading_ExecutionContext_RunInternal_System_Threading_ExecutionContext_System_Threading_ContextCallback_object_bool + 4339448060
  32 someNameSpace.iOS                     0x10325f6fc System_Threading_ExecutionContext_Run_System_Threading_ExecutionContext_System_Threading_ContextCallback_object_bool + 4339447548
  33 someNameSpace.iOS                     0x1032df1d8 System_Runtime_CompilerServices_AsyncMethodBuilderCore_MoveNextRunner_Run + 4339970520
  34 someNameSpace.iOS                     0x10327ea08 System_Threading_Tasks_SynchronizationContextAwaitTaskContinuation__c___cctorb__7_0_object + 4339575304
  35 someNameSpace.iOS                     0x104174c6c Foundation_NSAsyncSynchronizationContextDispatcher_Apply + 178 (NSAction.cs:178)
  36 someNameSpace.iOS                     0x103538880 wrapper_runtime_invoke_object_runtime_invoke_dynamic_intptr_intptr_intptr_intptr + 4342433920
  37 someNameSpace.iOS                     0x10558b21c mono_jit_runtime_invoke + 3165 (mini-runtime.c:3165)
  38 someNameSpace.iOS                     0x105646940 mono_runtime_invoke_checked + 3052 (object.c:3052)
  39 someNameSpace.iOS                     0x10564a1a4 mono_runtime_invoke + 3107 (object.c:3107)
  40 someNameSpace.iOS                     0x10310d3c8 native_to_managed_trampoline_11(objc_object*, objc_selector*, _MonoMethod**, unsigned int) + 408 (registrar.m:408)
  41 someNameSpace.iOS                     0x103113f8c -[__MonoMac_NSAsyncSynchronizationContextDispatcher xamarinApplySelector] + 9024 (registrar.m:9024)
  42 Foundation                     0x1966b7b90 __NSThreadPerformPerform + 188
  43 CoreFoundation                 0x19529d76c __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 28
  44 CoreFoundation                 0x19529d668 __CFRunLoopDoSource0 + 208
  45 CoreFoundation                 0x19529c9cc __CFRunLoopDoSources0 + 376
  46 CoreFoundation                 0x195296a8c __CFRunLoopRun + 824
  47 CoreFoundation                 0x19529621c CFRunLoopRunSpecific + 600
  48 GraphicsServices               0x1ace60784 GSEventRunModal + 164
  49 UIKitCore                      0x197cd6ee8 -[UIApplication _run] + 1072
  50 UIKitCore                      0x197cdc75c UIApplicationMain + 168
  51 someNameSpace.iOS                     0x1041e7ca8 wrapper_managed_to_native_UIKit_UIApplication_UIApplicationMain_int_string___intptr_intptr + 4355734696
  52 someNameSpace.iOS                     0x10411d6d0 UIKit_UIApplication_Main_string___intptr_intptr + 86 (UIApplication.cs:86)
  53 someNameSpace.iOS                     0x10411d654 UIKit_UIApplication_Main_string___string_string + 66 (UIApplication.cs:66)
  54 someNameSpace.iOS                     0x103141e64 someNameSpace._iOS_Application_Main_string__ + 1 (&lt;unknown&gt;:1)
  55 someNameSpace.iOS                     0x103538880 wrapper_runtime_invoke_object_runtime_invoke_dynamic_intptr_intptr_intptr_intptr + 4342433920
  56 someNameSpace.iOS                     0x10558b21c mono_jit_runtime_invoke + 3165 (mini-runtime.c:3165)
  57 someNameSpace.iOS                     0x105646940 mono_runtime_invoke_checked + 3052 (object.c:3052)
  58 someNameSpace.iOS                     0x10564cb98 mono_runtime_exec_main_checked + 5178 (object.c:5178)
  59 someNameSpace.iOS                     0x1055697b0 mono_jit_exec + 1383 (driver.c:1383)
  60 someNameSpace.iOS                     0x105727350 xamarin_main + 493 (monotouch-main.m:493)
  61 someNameSpace.iOS                     0x10313de40 main + 190 (main.m:190)
  62 libdyld.dylib                  0x194f566b0 start + 4
  </code></pre>