Xamarin Forms iOS App Crashing on Startup

Question

We have a user that is unable to open our app on their iPhone. They have uninstalled and reinstalled several times with multiple different versions but the app crashes as soon as it tries to start. This has happened for them on iOS 14.8 and still happening when they updated to iOS 15.1. They have provided us with the crash log from their phone which shows this. Does anyone have any ideas what could cause this?

Date/Time: 2021-12-03T15:19:03.214Z
Launch Time: 2021-12-03T02:44:59.014Z
OS Version: iPhone OS 15.1 (19B74)
Report Version: 104

Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000 at
Crashed Thread: 0

Thread 0 Crashed:
0 libsystem_kernel.dylib 0x00000001b84d0964 __pthread_kill + 8
1 libsystem_pthread.dylib 0x00000001f1930378 pthread_kill + 264
2 libsystem_c.dylib 0x000000018c51e420 __abort + 124
3 libsystem_c.dylib 0x000000018c4c6f5c abort + 172
4 OurAppiOS 0x00000001054990a4 xamarin_unhandled_exception_handler (runtime.m:1153)
5 OurAppiOS 0x000000010535dff8 mono_invoke_unhandled_exception_hook (exception.c:1265)
6 OurAppiOS 0x00000001052f2dc4 mono_handle_exception_internal (mini-exceptions.c:2782)
7 OurAppiOS 0x00000001052f37a4 mono_resume_unwind (mini-exceptions.c:3523)
8 OurAppiOS 0x00000001052e76e4 mono_arm_resume_unwind (exceptions-arm64.c:420)
9 OurAppiOS 0x0000000102963168 llvm_resume_unwind_trampoline + 164
10 OurAppiOS 0x000000010392b4ec Xamarin_iOS_UIKit_UIApplication_Main_string___string_string (UIApplication.cs:0)
11 OurAppiOS 0x00000001053049e8 mono_jit_runtime_invoke (mini-runtime.c:3164)
12 OurAppiOS 0x00000001053c010c mono_runtime_invoke_checked (object.c:3052)
13 OurAppiOS 0x00000001053c6364 mono_runtime_exec_main_checked (object.c:0)
14 OurAppiOS 0x00000001052e2f7c mono_jit_exec (driver.c:1383)
15 OurAppiOS 0x00000001054a0dac xamarin_main (monotouch-main.m:493)
16 OurAppiOS 0x000000010285510c main (main.m:302)
17 dyld 0x0000000105c39a24 start + 520 (dyldMain.cpp:876)

Thread 1:
0 libsystem_pthread.dylib 0x00000001f1929e8c start_wqthread + 0

Thread 2:
0 libsystem_kernel.dylib 0x00000001b84caf90 __psynch_cvwait + 8
1 libsystem_pthread.dylib 0x00000001f1931254 _pthread_cond_wait + 1224
2 OurAppiOS 0x0000000105463a7c thread_func (mono-os-mutex.h:219)
3 libsystem_pthread.dylib 0x00000001f192a9a4 _pthread_start + 144
4 libsystem_pthread.dylib 0x00000001f1929ea0 thread_start + 4

Thread 3:
0 libsystem_kernel.dylib 0x00000001b84ca540 semaphore_wait_trap + 8
1 OurAppiOS 0x000000010536137c finalizer_thread (mono-os-semaphore.h:84)
2 OurAppiOS 0x000000010540e0f8 start_wrapper_internal (threads.c:1233)
3 OurAppiOS 0x000000010540df7c start_wrapper (threads.c:1308)
4 libsystem_pthread.dylib 0x00000001f192a9a4 _pthread_start + 144
5 libsystem_pthread.dylib 0x00000001f1929ea0 thread_start + 4

Thread 4:
0 libsystem_kernel.dylib 0x00000001b84cb1a4 ulock_wait + 8
1 libdispatch.dylib 0x00000001812fc054 _dlock_wait + 52
2 libdispatch.dylib 0x00000001812fbdf8 _dispatch_thread_event_wait_slow + 52
3 libdispatch.dylib 0x000000018130ab9c __DISPATCH_WAIT_FOR_QUEUE + 360
4 libdispatch.dylib 0x000000018130a744 _dispatch_sync_f_slow + 140
5 UIKitCore 0x0000000183e08398 37-[_UIRemoteKeyboards startConnection]_block_invoke_3 + 132
6 CoreFoundation 0x00000001816122f4 __invoking_ + 144
7 CoreFoundation 0x000000018162fac4 -[NSInvocation invoke] + 464
8 Foundation 0x0000000182e46f00 NSXPCCONNECTION_IS_CALLING_OUT_TO_REPLY_BLOCK + 20
9 Foundation 0x0000000182e67da4 -[NSXPCConnection _decodeAndInvokeReplyBlockWithEvent:sequence:replyInfo:] + 552
10 Foundation 0x0000000182e42a84 __88-[NSXPCConnection _sendInvocation:orArguments:count:methodSignature:selector:withProxy:]_block_invoke_3 + 208
11 libxpc.dylib 0x00000001f196032c _xpc_connection_reply_callout + 112
12 libxpc.dylib 0x00000001f195385c _xpc_connection_call_reply_async + 84
13 libdispatch.dylib 0x00000001812fb6e0 _dispatch_client_callout3 + 16
14 libdispatch.dylib 0x0000000181318ec8 _dispatch_mach_msg_async_reply_invoke + 344
15 libdispatch.dylib 0x0000000181302cbc _dispatch_lane_serial_drain + 372
16 libdispatch.dylib 0x000000018130398c _dispatch_lane_invoke + 440
17 libdispatch.dylib 0x000000018130e1a8 _dispatch_workloop_worker_thread + 652
18 libsystem_pthread.dylib 0x00000001f192a0f4 _pthread_wqthread + 284
19 libsystem_pthread.dylib 0x00000001f1929e94 start_wqthread + 4

Thread 5:
0 libsystem_pthread.dylib 0x00000001f1929e8c start_wqthread + 0

Thread 6:
0 libsystem_kernel.dylib 0x00000001b84ca504 mach_msg_trap + 8
1 libsystem_kernel.dylib 0x00000001b84cab9c mach_msg + 72
2 CoreFoundation 0x00000001815f7688 CFRunLoopServiceMachPort + 368
3 CoreFoundation 0x00000001815fb97c __CFRunLoopRun + 1208
4 CoreFoundation 0x000000018160f3b8 CFRunLoopRunSpecific + 596
5 Foundation 0x0000000182e2a354 -[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 232
6 Foundation 0x0000000182e6bc28 -[NSRunLoop(NSRunLoop) runUntilDate:] + 88
7 UIKitCore 0x0000000183f288a4 -[UIEventFetcher threadMain] + 520
8 Foundation 0x0000000182e7a36c __NSThread__start + 804
9 libsystem_pthread.dylib 0x00000001f192a9a4 _pthread_start + 144
10 libsystem_pthread.dylib 0x00000001f1929ea0 thread_start + 4

Thread 7:
0 libsystem_pthread.dylib 0x00000001f1929e8c start_wqthread + 0

Thread 8:
0 libsystem_pthread.dylib 0x00000001f1929e8c start_wqthread + 0

Thread 9:
0 libsystem_pthread.dylib 0x00000001f1929e8c start_wqthread + 0

Thread 10:
0 libsystem_pthread.dylib 0x00000001f1929e8c start_wqthread + 0

Thread 11:
0 libsystem_pthread.dylib 0x00000001f1929e8c start_wqthread + 0

Thread 12:
0 libsystem_pthread.dylib 0x00000001f1929e8c start_wqthread + 0

Thread 13:
0 libsystem_pthread.dylib 0x00000001f1929e8c start_wqthread + 0

Thread 14:
0 libsystem_pthread.dylib 0x00000001f1929e8c start_wqthread + 0

Thread 15:
0 libsystem_pthread.dylib 0x00000001f1929e8c start_wqthread + 0

Thread 16:
0 libsystem_pthread.dylib 0x00000001f1929e8c start_wqthread + 0

Thread 17:
0 libsystem_pthread.dylib 0x00000001f1929e8c start_wqthread + 0

Thread 18:
0 libsystem_pthread.dylib 0x00000001f1929e8c start_wqthread + 0

Thread 19:
0 libsystem_pthread.dylib 0x00000001f1929e8c start_wqthread + 0

Thread 20:
0 libsystem_pthread.dylib 0x00000001f1929e8c start_wqthread + 0

Thread 21:
0 libsystem_pthread.dylib 0x00000001f1929e8c start_wqthread + 0

Thread 22:
0 libsystem_pthread.dylib 0x00000001f1929e8c start_wqthread + 0

Thread 23:
0 libsystem_pthread.dylib 0x00000001f1929e8c start_wqthread + 0

Thread 24:
0 libsystem_pthread.dylib 0x00000001f1929e8c start_wqthread + 0

Thread 25:
0 libsystem_pthread.dylib 0x00000001f1929e8c start_wqthread + 0

Thread 0 crashed with ARM-64 (Native) Thread State:
x0: 0x0000000000000000 x1: 0x0000000000000000 x2: 0x0000000000000000 x3: 0x0000000000000000
x4: 0x0000000000000000 x5: 0x0000000000989680 x6: 0x0000000000000600 x7: 0xffffffff00000400
x8: 0x1ff943a14f4a1322 x9: 0x1ff943a04a8256a2 x10: 0x00000000000003e8 x11: 0x0000000000bf3d01
x12: 0x0000000000004009 x13: 0x0000000107174000 x14: 0x0000000000003fff x15: 0x0000000000003381
x16: 0x0000000000000148 x17: 0x0000000105c84580 x18: 0x0000000000000000 x19: 0x0000000000000006
x20: 0x0000000000000103 x21: 0x0000000105c84660 x22: 0x0000000106409a30 x23: 0x0000000107022e48
x24: 0x0000000107131f50 x25: 0x0000000106776900 x26: 0x000000010701ac00 x27: 0x0000000000000003
x28: 0x00000001029396bf fp: 0x000000016d6cd650 lr: 0x00000001f1930378 sp: 0x000000016d6cd630
pc: 0x00000001b84d0964 cpsr: 0x40000000 esr: 0x56000080