An iOS app crashes on a device for an unknown reason

Some users reported that when an app crashes on their devices, they try to localize it. But I cannot reproduce this problem. I got a couple of such crashes (from Crashlytics) that I can't figure out.

Anyone can understand what this is about?

#0. Crashed: com.twitter.crashlytics.ios.exception
0  5580-THV-Economics         0x10015056c CLSProcessRecordAllThreads + 1572
1  5580-THV-Economics         0x10015056c CLSProcessRecordAllThreads + 1572
2  5580-THV-Economics         0x100150428 CLSProcessRecordAllThreads + 1248
3  5580-THV-Economics         0x10014058c CLSHandler + 48
4  5580-THV-Economics         0x10014e568 __CLSExceptionRecord_block_invoke + 92
5  libdispatch.dylib              0x18be0a9a0 _dispatch_client_callout + 16
6  libdispatch.dylib              0x18be17ee0 _dispatch_barrier_sync_f_invoke + 84
7  5580-THV-Economics         0x10014e00c CLSExceptionRecord + 212
8  5580-THV-Economics         0x10014de40 CLSExceptionRecordNSException + 548
9  5580-THV-Economics         0x10014da60 CLSTerminateHandler() + 396
10 libc++abi.dylib                0x18b9a35d4 std::__terminate(void (*)()) + 16
11 libc++abi.dylib                0x18b9a31a8 __cxa_rethrow + 144
12 libobjc.A.dylib                0x18b9b46f8 objc_exception_rethrow + 44
13 CoreFoundation                 0x18ce2ee00 CFRunLoopRunSpecific + 532
14 GraphicsServices               0x18e898074 GSEventRunModal + 100
15 UIKit                          0x1930e0130 UIApplicationMain + 208
16 5580-THV-Economics         0x1000798fc main (main.m:14)
17 libdyld.dylib                  0x18be3d59c start + 4

--

Fatal Exception: NSInternalInconsistencyException
0  CoreFoundation                 0x18cf52fd8 __exceptionPreprocess
1  libobjc.A.dylib                0x18b9b4538 objc_exception_throw
2  CoreFoundation                 0x18cf52eac +[NSException raise:format:]
3  Foundation                     0x18d9ea710 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:]
4  FrontBoardServices             0x18eae4940 -[FBSSettingsDiffInspector inspectDiff:withContext:]
5  UIKit                          0x1932fd550 __70-[UIApplication scene:didUpdateWithDiff:transitionContext:completion:]_block_invoke
6  UIKit                          0x1932fd1ec -[UIApplication scene:didUpdateWithDiff:transitionContext:completion:]
7  UIKit                          0x1936376e4 -[UIApplicationSceneClientAgent scene:handleEvent:withCompletion:]
8  FrontBoardServices             0x18eace22c __80-[FBSSceneImpl updater:didUpdateSettings:withDiff:transitionContext:completion:]_block_invoke.376
9  FrontBoardServices             0x18eafb884 __FBSSERIALQUEUE_IS_CALLING_OUT_TO_A_BLOCK__
10 FrontBoardServices             0x18eafb6f0 -[FBSSerialQueue _performNext]
11 FrontBoardServices             0x18ead4414 -[FBSWorkspace synchronizeSystemAnimationFencesWithCleanUpBlock:]
12 UIKit                          0x1932f9434 -[UIApplication _synchronizeSystemAnimationFencesWithSpinCleanUpBlock:]
13 UIKit                          0x19334f7f8 __realPreCommitHandler_block_invoke
14 QuartzCore                     0x190200808 CA::Transaction::Fence::run_callbacks() const
15 QuartzCore                     0x1901d8440 CA::Context::commit_transaction(CA::Transaction*)
16 QuartzCore                     0x1901ff3c0 CA::Transaction::commit()
17 a.dylib                        0x1004e69d0 (Missing)
18 a.dylib                        0x1004e9a9c (Missing)
19 CoreFoundation                 0x18ceed5ec __CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__
20 CoreFoundation                 0x18ceecd00 _CFXRegistrationPost
21 CoreFoundation                 0x18ceeca7c ___CFXNotificationPost_block_invoke
22 CoreFoundation                 0x18cf5b7a8 -[_CFXNotificationRegistrar find:object:observer:enumerator:]
23 CoreFoundation                 0x18ce3094c _CFXNotificationPost
24 Foundation                     0x18d942920 -[NSNotificationCenter postNotificationName:object:userInfo:]
25 UIKit                          0x1930e208c -[UIApplication _deactivateForReason:notify:]
26 UIKit                          0x1932fc0f8 __61-[UIApplication _sceneSettingsPreLifecycleEventDiffInspector]_block_invoke
27 FrontBoardServices             0x18eae4be8 __52-[FBSSettingsDiffInspector inspectDiff:withContext:]_block_invoke.27
28 Foundation                     0x18d9fc7ec __NSIndexSetEnumerate
29 BaseBoard                      0x18ea576e8 -[BSSettingsDiff inspectChangesWithBlock:]
30 FrontBoardServices             0x18eadece4 -[FBSSettingsDiff inspectOtherChangesWithBlock:]
31 FrontBoardServices             0x18eae49bc -[FBSSettingsDiffInspector inspectDiff:withContext:]
32 UIKit                          0x1932fd550 __70-[UIApplication scene:didUpdateWithDiff:transitionContext:completion:]_block_invoke
33 UIKit                          0x1932fd1ec -[UIApplication scene:didUpdateWithDiff:transitionContext:completion:]
34 UIKit                          0x1936376e4 -[UIApplicationSceneClientAgent scene:handleEvent:withCompletion:]
35 FrontBoardServices             0x18eace22c __80-[FBSSceneImpl updater:didUpdateSettings:withDiff:transitionContext:completion:]_block_invoke.376
36 FrontBoardServices             0x18eafb884 __FBSSERIALQUEUE_IS_CALLING_OUT_TO_A_BLOCK__
37 FrontBoardServices             0x18eafb6f0 -[FBSSerialQueue _performNext]
38 FrontBoardServices             0x18eafbaa0 -[FBSSerialQueue _performNextFromRunLoopSource]
39 CoreFoundation                 0x18cf01424 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__
40 CoreFoundation                 0x18cf00d94 __CFRunLoopDoSources0
41 CoreFoundation                 0x18cefe9a0 __CFRunLoopRun
42 CoreFoundation                 0x18ce2ed94 CFRunLoopRunSpecific
43 GraphicsServices               0x18e898074 GSEventRunModal
44 UIKit                          0x1930e0130 UIApplicationMain
45 5580-THV-Economics         0x1000798fc main (main.m:14)
46 libdyld.dylib                  0x18be3d59c start