Incident Identifier: b6e0e9ee-c79a-471a-afc9-8d8c5b5e30e2
CrashReporter Key:   990d56c9-d236-4d67-b44b-e09f06847d2a
Hardware Model:      iPhone8,1
Process:         iSurvey.iOS [744]
Path:            /var/containers/Bundle/Application/D49AAB3C-B826-4EA6-9723-27DF46B99977/iSurvey.iOS.app/iSurvey.iOS
Identifier:      com.survey.isurvey
Version:         4.25.11 (4.25.11)
Code Type:       arm64
Parent Process:  ??? [1]

Date/Time:       2018-08-21T22:36:26.999Z
Launch Time:     2018-08-21T22:34:50Z
OS Version:      iPhone OS 11.4.1 (15G77)
Report Version:  104

Exception Type:  SIGABRT
Exception Codes: #0 at 0x181c4d2e0
Crashed Thread:  0

Xamarin Exception Stack:
System.NullReferenceException: Object reference not set to an instance of an object
  at Xamarin.Forms.Platform.iOS.EntryRenderer.UpdateCursorFromControl (Foundation.NSObservedChange obj) <0x104ed0620 + 0x00044> in <e4b6f1dd03224a8e9d9ccd926c676fb9#93f9e50eb0867b850fed0909f39c219e>:0
  at Foundation.NSObject+Observer.ObserveValue (Foundation.NSString keyPath, Foundation.NSObject ofObject, Foundation.NSDictionary change, System.IntPtr context) <0x1072a7350 + 0x000af> in <0b60c1467e7449608ac42f9c7bbfdd05#93f9e50eb0867b850fed0909f39c219e>:0
  at (wrapper managed-to-native) UIKit.UIApplication.UIApplicationMain(int,string[],intptr,intptr)
  at UIKit.UIApplication.Main (System.String[] args, System.IntPtr principal, System.IntPtr delegate) <0x107255e00 + 0x0002b> in <0b60c1467e7449608ac42f9c7bbfdd05#93f9e50eb0867b850fed0909f39c219e>:0
  at UIKit.UIApplication.Main (System.String[] args, System.String principalClassName, System.String delegateClassName) <0x107255d40 + 0x000ab> in <0b60c1467e7449608ac42f9c7bbfdd05#93f9e50eb0867b850fed0909f39c219e>:0
  at iSurvey.iOS.Application.Main (System.String[] args) <0x104c2d770 + 0x00023> in <7901a02fb2684ebdb80f15626b3977d4#93f9e50eb0867b850fed0909f39c219e>:0

Thread 0 Crashed:
0   libsystem_kernel.dylib               0x0000000181c4d2e0 __pthread_kill + 8
1   libsystem_c.dylib                    0x0000000181bbbd0c abort + 136
2   Xamarin                              0x00000001067a79fc 0x106798000 + 63996
3   Mono                                 0x0000000106597ef0 0x1064fc000 + 638704
4   Mono                                 0x000000010654d644 0x1064fc000 + 333380
5   Mono                                 0x000000010654c38c 0x1064fc000 + 328588
6   Mono                                 0x0000000106543394 0x1064fc000 + 291732
7   iSurvey.iOS                          0x0000000104ed065c Xamarin_Forms_Platform_iOS_EntryRenderer_UpdateCursorFromControl_Foundation_NSObservedChange (<unknown>:1)
8   Xamarin.Sdk                          0x00000001072a7400 0x1067f8000 + 11203584
9   Xamarin.Sdk                          0x0000000106ad5ba8 0x1067f8000 + 3005352
10  Mono                                 0x000000010655d778 0x1064fc000 + 399224
11  Mono                                 0x00000001065dc8a4 0x1064fc000 + 919716
12  Mono                                 0x00000001065e00c0 0x1064fc000 + 934080
13  iSurvey.iOS                          0x0000000104c03598 native_to_managed_trampoline_59(objc_object*, objc_selector*, _MonoMethod**, NSString*, NSObject*, NSDictionary*, void*, unsigned int) (registrar.m:2929)
14  iSurvey.iOS                          0x0000000104c19c08 -[__XamarinObjectObserver observeValueForKeyPath:ofObject:change:context:] (registrar.m:16031)
15  Foundation                           0x0000000182b552f8 NSKeyValueNotifyObserver + 300
16  Foundation                           0x0000000182b54e30 NSKeyValueDidChange + 376
17  Foundation                           0x0000000182b2c5a4 -[NSObject(NSKeyValueObservingPrivate) _changeValueForKeys:count:maybeOldValuesDict:usingBlock:] + 660
18  Foundation                           0x0000000182b54534 -[NSObject(NSKeyValueObservingPrivate) _changeValueForKey:key:key:usingBlock:] + 56
19  Foundation                           0x0000000182b66470 _NSSetObjectValueAndNotify + 268
20  UIKit                                0x000000018c4bb5a0 -[UITextDragAssistant _liftOrDrag:didEndWithOperation:] + 88
21  UIKit                                0x000000018c4bb51c -[UITextDragAssistant dragInteraction:session:didEndWithOperation:] + 324
22  UIKit                                0x000000018c5b4030 -[UIDragInteraction _sessionDidEnd:withOperation:] + 164
23  UIKit                                0x000000018c626a40 -[_UIDragSessionImpl draggingSessionDidEnd:withOperation:] + 236
24  UIKit                                0x000000018ca5f00c -[_UIDraggingSession _sendDidEndWithOperation:] + 132
25  UIKit                                0x000000018ca61b04 -[_UIInternalDraggingSessionSource setState:] + 844
26  UIKit                                0x000000018c31b690 -[_UIDragSetDownAnimation _allAnimationItemsDone] + 52
27  UIKit                                0x000000018c31b610 -[_UIDragSetDownAnimation _animationItemDone:] + 492
28  UIKit                                0x000000018c1bd884 _runAfterCACommitDeferredBlocks + 292
29  UIKit                                0x000000018c1b3958 _cleanUpAfterCAFlushAndRunDeferredBlocks + 380
30  UIKit                                0x000000018c09851c _afterCACommitHandler + 128
31  CoreFoundation                       0x000000018216e910 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 28
32  CoreFoundation                       0x000000018216c238 __CFRunLoopDoObservers + 408
33  CoreFoundation                       0x000000018216c884 __CFRunLoopRun + 1432
34  CoreFoundation                       0x000000018208cda8 CFRunLoopRunSpecific + 548
35  GraphicsServices                     0x0000000184072020 GSEventRunModal + 96
36  UIKit                                0x000000018c0ac758 UIApplicationMain + 232
37  Xamarin.Sdk                          0x0000000107300ab0 0x1067f8000 + 11569840
38  Xamarin.Sdk                          0x0000000107255e2c 0x1067f8000 + 10870316
39  Xamarin.Sdk                          0x0000000107255dec 0x1067f8000 + 10870252
40  iSurvey.iOS                          0x0000000104c2d794 iSurvey_iOS_Application_Main_string__ (<unknown>:1)
41  Xamarin.Sdk                          0x0000000106ad5ba8 0x1067f8000 + 3005352
42  Mono                                 0x000000010655d778 0x1064fc000 + 399224
43  Mono                                 0x00000001065dc8a4 0x1064fc000 + 919716
44  Mono                                 0x00000001065e261c 0x1064fc000 + 943644
45  Mono                                 0x000000010653f608 0x1064fc000 + 275976
46  Xamarin                              0x00000001067aed0c 0x106798000 + 93452
47  iSurvey.iOS                          0x0000000104c2d314 main (main.m:206)
48  libdyld.dylib                        0x0000000181b1dfc0 start + 0

Thread 1:
0   libsystem_kernel.dylib               0x0000000181c4dd78 __workq_kernreturn + 8
1   libsystem_pthread.dylib              0x0000000181debb08 start_wqthread + 0

Thread 2:
0   libsystem_kernel.dylib               0x0000000181c4d0e8 __psynch_cvwait + 8
1   libc++.1.dylib                       0x000000018130425c std::__1::condition_variable::wait(std::__1::unique_lock<std::__1::mutex>&) + 20
2   JavaScriptCore                       0x000000018981545c void std::__1::condition_variable_any::wait<std::__1::unique_lock<bmalloc::Mutex> >(std::__1::unique_lock<bmalloc::Mutex>&) + 100
3   JavaScriptCore                       0x0000000189815070 bmalloc::Scavenger::threadRunLoop() + 160
4   JavaScriptCore                       0x0000000189814e18 bmalloc::Scavenger::threadEntryPoint(bmalloc::Scavenger*) + 8
5   JavaScriptCore                       0x0000000189815234 void* std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, void (*)(bmalloc::Scavenger*), bmalloc::Scavenger*> >(void*) + 40
6   libsystem_pthread.dylib              0x0000000181ded220 _pthread_body + 268
7   libsystem_pthread.dylib              0x0000000181ded110 _pthread_start + 288
8   libsystem_pthread.dylib              0x0000000181debb10 thread_start + 0

Thread 3:
0   libsystem_kernel.dylib               0x0000000181c2bde8 mach_msg_trap + 8
1   CoreFoundation                       0x000000018216ee40 __CFRunLoopServiceMachPort + 192
2   CoreFoundation                       0x000000018216c908 __CFRunLoopRun + 1564
3   CoreFoundation                       0x000000018208cda8 CFRunLoopRunSpecific + 548
4   WebCore                              0x000000018a3502d4 RunWebThread(void*) + 588
5   libsystem_pthread.dylib              0x0000000181ded220 _pthread_body + 268
6   libsystem_pthread.dylib              0x0000000181ded110 _pthread_start + 288
7   libsystem_pthread.dylib              0x0000000181debb10 thread_start + 0

Thread 4:
0   libsystem_kernel.dylib               0x0000000181c4d0e8 __psynch_cvwait + 8
1   Mono                                 0x000000010666e438 0x1064fc000 + 1516600
2   libsystem_pthread.dylib              0x0000000181ded220 _pthread_body + 268
3   libsystem_pthread.dylib              0x0000000181ded110 _pthread_start + 288
4   libsystem_pthread.dylib              0x0000000181debb10 thread_start + 0

Thread 5:
0   libsystem_kernel.dylib               0x0000000181c2be24 semaphore_wait_trap + 8
1   Mono                                 0x0000000106615ef0 0x1064fc000 + 1154800
2   libsystem_pthread.dylib              0x0000000181ded220 _pthread_body + 268
3   libsystem_pthread.dylib              0x0000000181ded110 _pthread_start + 288
4   libsystem_pthread.dylib              0x0000000181debb10 thread_start + 0

Thread 6:
0   libsystem_kernel.dylib               0x0000000181c2bde8 mach_msg_trap + 8
1   CoreFoundation                       0x000000018216ee40 __CFRunLoopServiceMachPort + 192
2   CoreFoundation                       0x000000018216c908 __CFRunLoopRun + 1564
3   CoreFoundation                       0x000000018208cda8 CFRunLoopRunSpecific + 548
4   Foundation                           0x0000000182b01674 -[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 300
5   Foundation                           0x0000000182b0151c -[NSRunLoop(NSRunLoop) runUntilDate:] + 144
6   UIKit                                0x000000018bd91768 -[UIEventFetcher threadMain] + 132
7   Foundation                           0x0000000182c11efc __NSThread__start__ + 1036
8   libsystem_pthread.dylib              0x0000000181ded220 _pthread_body + 268
9   libsystem_pthread.dylib              0x0000000181ded110 _pthread_start + 288
10  libsystem_pthread.dylib              0x0000000181debb10 thread_start + 0

Thread 7:
0   libsystem_kernel.dylib               0x0000000181c4dd78 __workq_kernreturn + 8
1   libsystem_pthread.dylib              0x0000000181debb08 start_wqthread + 0

Thread 8:
0   libsystem_kernel.dylib               0x0000000181c2bde8 mach_msg_trap + 8
1   CoreFoundation                       0x000000018216ee40 __CFRunLoopServiceMachPort + 192
2   CoreFoundation                       0x000000018216c908 __CFRunLoopRun + 1564
3   CoreFoundation                       0x000000018208cda8 CFRunLoopRunSpecific + 548
4   Foundation                           0x0000000182b01674 -[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 300
5   Foundation                           0x0000000182b761a8 -[NSRunLoop(NSRunLoop) run] + 84
6   iSurvey.iOS                          0x0000000105b92a98 +[GAI threadMain:] + 60
7   Foundation                           0x0000000182c11efc __NSThread__start__ + 1036
8   libsystem_pthread.dylib              0x0000000181ded220 _pthread_body + 268
9   libsystem_pthread.dylib              0x0000000181ded110 _pthread_start + 288
10  libsystem_pthread.dylib              0x0000000181debb10 thread_start + 0

Thread 9:
0   libsystem_kernel.dylib               0x0000000181c4d0e8 __psynch_cvwait + 8
1   Mono                                 0x000000010667aaec 0x1064fc000 + 1567468
2   Mono                                 0x00000001066208c4 0x1064fc000 + 1198276
3   Mono                                 0x00000001066207ac 0x1064fc000 + 1197996
4   Mono                                 0x00000001066209c4 0x1064fc000 + 1198532
5   Mono                                 0x00000001066115dc 0x1064fc000 + 1136092
6   Xamarin.Sdk                          0x00000001069840a8 0x1067f8000 + 1622184
7   Xamarin.Sdk                          0x0000000106983fa8 0x1067f8000 + 1621928
8   Xamarin.Sdk                          0x0000000106983dbc 0x1067f8000 + 1621436
9   Xamarin.Sdk                          0x0000000106983d68 0x1067f8000 + 1621352
10  Xamarin.Sdk                          0x0000000106983b7c 0x1067f8000 + 1620860
11  Xamarin.Sdk                          0x0000000106983cd8 0x1067f8000 + 1621208
12  Xamarin.Sdk                          0x0000000106987464 0x1067f8000 + 1635428
13  Xamarin.Sdk                          0x000000010697dfcc 0x1067f8000 + 1597388
14  Xamarin.Sdk                          0x000000010697bbf4 0x1067f8000 + 1588212
15  Xamarin.Sdk                          0x000000010697ba4c 0x1067f8000 + 1587788
16  Xamarin.Sdk                          0x000000010697b9cc 0x1067f8000 + 1587660
17  Xamarin.Sdk                          0x000000010697e134 0x1067f8000 + 1597748
18  Xamarin.Sdk                          0x0000000106ad5ba8 0x1067f8000 + 3005352
19  Mono                                 0x000000010655d778 0x1064fc000 + 399224
20  Mono                                 0x00000001065dc8a4 0x1064fc000 + 919716
21  Mono                                 0x0000000106615f14 0x1064fc000 + 1154836
22  libsystem_pthread.dylib              0x0000000181ded220 _pthread_body + 268
23  libsystem_pthread.dylib              0x0000000181ded110 _pthread_start + 288
24  libsystem_pthread.dylib              0x0000000181debb10 thread_start + 0

Thread 10:
0   libsystem_kernel.dylib               0x0000000181c4d52c __select + 8
1   Mono                                 0x00000001066093c0 0x1064fc000 + 1102784
2   Mono                                 0x0000000106608dd8 0x1064fc000 + 1101272
3   Mono                                 0x0000000106615ef0 0x1064fc000 + 1154800
4   libsystem_pthread.dylib              0x0000000181ded220 _pthread_body + 268
5   libsystem_pthread.dylib              0x0000000181ded110 _pthread_start + 288
6   libsystem_pthread.dylib              0x0000000181debb10 thread_start + 0

Thread 11:
0   libsystem_kernel.dylib               0x0000000181c2bde8 mach_msg_trap + 8
1   CoreFoundation                       0x000000018216ee40 __CFRunLoopServiceMachPort + 192
2   CoreFoundation                       0x000000018216c908 __CFRunLoopRun + 1564
3   CoreFoundation                       0x000000018208cda8 CFRunLoopRunSpecific + 548
4   CFNetwork                            0x000000018299a6e0 -[__CoreSchedulingSetRunnable runForever] + 216
5   Foundation                           0x0000000182c11efc __NSThread__start__ + 1036
6   libsystem_pthread.dylib              0x0000000181ded220 _pthread_body + 268
7   libsystem_pthread.dylib              0x0000000181ded110 _pthread_start + 288
8   libsystem_pthread.dylib              0x0000000181debb10 thread_start + 0

Thread 12:
0   libsystem_kernel.dylib               0x0000000181c4d0e8 __psynch_cvwait + 8
1   Mono                                 0x000000010667aaec 0x1064fc000 + 1567468
2   Mono                                 0x00000001066208c4 0x1064fc000 + 1198276
3   Mono                                 0x00000001066207ac 0x1064fc000 + 1197996
4   Mono                                 0x00000001065cffdc 0x1064fc000 + 868316
5   Xamarin.Sdk                          0x000000010697d668 0x1067f8000 + 1594984
6   Xamarin.Sdk                          0x000000010697d710 0x1067f8000 + 1595152
7   Xamarin.Sdk                          0x000000010697d23c 0x1067f8000 + 1593916
8   Xamarin.Sdk                          0x000000010697d290 0x1067f8000 + 1594000
9   Xamarin.Sdk                          0x0000000106977fb8 0x1067f8000 + 1572792
10  Xamarin.Sdk                          0x0000000106977d34 0x1067f8000 + 1572148
11  Xamarin.Sdk                          0x0000000106dcfda0 0x1067f8000 + 6127008
12  Xamarin.Sdk                          0x0000000106dcfba8 0x1067f8000 + 6126504
13  Xamarin.Sdk                          0x0000000106dcfadc 0x1067f8000 + 6126300
14  iSurvey.iOS                          0x0000000104ef8004 Xamarin_Forms_Platform_iOS_CADisplayLinkTicker_StartThread (<unknown>:1)
15  Xamarin.Sdk                          0x000000010697dfcc 0x1067f8000 + 1597388
16  Xamarin.Sdk                          0x000000010697bbf4 0x1067f8000 + 1588212
17  Xamarin.Sdk                          0x000000010697ba4c 0x1067f8000 + 1587788
18  Xamarin.Sdk                          0x000000010697b9cc 0x1067f8000 + 1587660
19  Xamarin.Sdk                          0x000000010697e134 0x1067f8000 + 1597748
20  Xamarin.Sdk                          0x0000000106ad5ba8 0x1067f8000 + 3005352
21  Mono                                 0x000000010655d778 0x1064fc000 + 399224
22  Mono                                 0x00000001065dc8a4 0x1064fc000 + 919716
23  Mono                                 0x0000000106615f14 0x1064fc000 + 1154836
24  libsystem_pthread.dylib              0x0000000181ded220 _pthread_body + 268
25  libsystem_pthread.dylib              0x0000000181ded110 _pthread_start + 288
26  libsystem_pthread.dylib              0x0000000181debb10 thread_start + 0

Thread 13:
0   libsystem_kernel.dylib               0x0000000181c4dd78 __workq_kernreturn + 8
1   libsystem_pthread.dylib              0x0000000181debb08 start_wqthread + 0

Thread 14:
0   libsystem_kernel.dylib               0x0000000181c4dd78 __workq_kernreturn + 8
1   libsystem_pthread.dylib              0x0000000181debb08 start_wqthread + 0

Thread 15:
0   libsystem_kernel.dylib               0x0000000181c4dd78 __workq_kernreturn + 8
1   libsystem_pthread.dylib              0x0000000181debb08 start_wqthread + 0

Thread 0 crashed with arm64 Thread State:
   x21: 0x000000016b2401d0     x2: 0x0000000000000000    x16: 0x0000000000000148     x3: 0x0000000000000003
   x22: 0x0000000000000303     x4: 0x0000000181bd24ef    x17: 0x0000000000000000   cpsr: 0x0000000000000000
    x5: 0x000000016b23f0d0    x23: 0x00000001b4558c20     x6: 0x0000000000000035    x18: 0x0000000000000000
   x10: 0x0000000181dee110     lr: 0x0000000181dee288     x7: 0xffffffffffffffec    x24: 0x0000000108343d88
   x11: 0x00000001b6905df4     x8: 0x0000000008000000    x19: 0x0000000000000006    x25: 0x0000000107700640
    x9: 0x0000000004000000    x12: 0x00000001b6905df4     fp: 0x000000016b23f3e0    x26: 0x000000011287a150
   x13: 0x0000000000000018     pc: 0x0000000181c4d2e0    x27: 0x0000000108821be8    x14: 0x0000000000000001
   x20: 0x00000001b4558b40     x0: 0x0000000000000000     sp: 0x000000016b23f3b0    x28: 0x0000000106ad5ba7
   x15: 0x0000000000000881     x1: 0x0000000000000000

Binary Images:
0x0000000104bbc000 -        0x0000000105f9ffff +iSurvey.iOS arm64  <e24691da-45ad-3771-8418-f98220dcab20> /var/containers/Bundle/Application/D49AAB3C-B826-4EA6-9723-27DF46B99977/iSurvey.iOS.app/iSurvey.iOS
0x00000001064fc000 -        0x000000010671bfff +Mono arm64  <133cbcd5-3395-3a4f-a6b4-83aa79e745c5> /private/var/containers/Bundle/Application/D49AAB3C-B826-4EA6-9723-27DF46B99977/iSurvey.iOS.app/Frameworks/Mono.framework/Mono
0x0000000106798000 -        0x00000001067b3fff +Xamarin arm64  <e62506f7-a60b-340f-ad3c-0da8a8d33539> /private/var/containers/Bundle/Application/D49AAB3C-B826-4EA6-9723-27DF46B99977/iSurvey.iOS.app/Frameworks/Xamarin.framework/Xamarin
0x00000001067f8000 -        0x000000010755bfff +Xamarin.Sdk arm64  <097dfafa-b8df-3644-a436-7ca790af5741> /private/var/containers/Bundle/Application/D49AAB3C-B826-4EA6-9723-27DF46B99977/iSurvey.iOS.app/Frameworks/Xamarin.Sdk.framework/Xamarin.Sdk
0x00000001812fd000 -        0x0000000181355fff  libc++.1.dylib arm64  <e6172d25-b5d6-3239-8794-10136730d916> /usr/lib/libc++.1.dylib
0x0000000181b1d000 -        0x0000000181b37fff  libdyld.dylib arm64  <6225b1cd-3984-3071-a64a-dd8f31b09c36> /usr/lib/system/libdyld.dylib
0x0000000181b59000 -        0x0000000181bd6fff  libsystem_c.dylib arm64  <61d2e950-add7-3139-aea4-59b55997ea48> /usr/lib/system/libsystem_c.dylib
0x0000000181c2b000 -        0x0000000181c53fff  libsystem_kernel.dylib arm64  <e102701e-f880-3cd4-a5d5-4f5f14433dbd> /usr/lib/system/libsystem_kernel.dylib
0x0000000181deb000 -        0x0000000181dfafff  libsystem_pthread.dylib arm64  <07c87e38-74b7-3d12-8f0f-a331d8894b97> /usr/lib/system/libsystem_pthread.dylib
0x0000000182081000 -        0x0000000182417fff  CoreFoundation arm64  <533c841e-d6e9-313d-8adb-02388744e2ef> /System/Library/Frameworks/CoreFoundation.framework/CoreFoundation
0x000000018274a000 -        0x0000000182af8fff  CFNetwork arm64  <ce119938-b410-382b-b448-1e599405ef23> /System/Library/Frameworks/CFNetwork.framework/CFNetwork
0x0000000182af9000 -        0x0000000182df1fff  Foundation arm64  <2eacef3c-b1e5-323e-ac1a-2e0d743c81a5> /System/Library/Frameworks/Foundation.framework/Foundation
0x0000000184067000 -        0x000000018407afff  GraphicsServices arm64  <5011ec25-11d7-3a56-af50-1e8207d54962> /System/Library/PrivateFrameworks/GraphicsServices.framework/GraphicsServices
0x0000000188d3f000 -        0x00000001898bdfff  JavaScriptCore arm64  <8be29f5e-e31a-302b-bc16-e47869e799ac> /System/Library/Frameworks/JavaScriptCore.framework/JavaScriptCore
0x000000018a30f000 -        0x000000018b9e1fff  WebCore arm64  <2fe41735-93ba-35c4-a5e0-4b40b40f1a7e> /System/Library/PrivateFrameworks/WebCore.framework/WebCore
0x000000018bd8f000 -        0x000000018ce0dfff  UIKit arm64  <be6ef020-3caa-3939-86da-6dd6737541d5> /System/Library/Frameworks/UIKit.framework/UIKit