The call stack is followed:
Incident Identifier: 5DBD18B5-29DD-48E1-8BE5-A648BD4E8CE3
CrashReporter Key: 4006fd6d63831c08be5068429b9892f633d41735
Hardware Model: iPhone12,5
Process: XXX
Path: /private/var/containers/Bundle/Application/FD114B6F-9C45-4546-9924-082A2CF546B8/XXX.app/XXX
Identifier: com.xxx.xxx
Version: 2.0.0 (2.0.0.3)
AppStoreTools: 13A227
AppVariant: 1:iPhone12,5:13
Code Type: ARM-64 (Native)
Role: Unspecified
Parent Process: launchd [1]
Coalition: com.xxx.xxx [2761]
Date/Time: 2021-09-28 14:24:03.8329 +0800
Launch Time: 2021-09-28 14:24:03.5890 +0800
OS Version: iPhone OS 15.0 (19A346)
Release Type: User
Baseband Version: 3.00.00
Report Version: 104
Exception Type: EXC_GUARD
Exception Subtype: GUARD_TYPE_USER
Exception Message: namespc 18 reason_code 0x0000000000000002
Exception Codes: 0x6000000000000012, 0x0000000000000002
Exception Note: SIMULATED (this is NOT a crash)
Termination Reason: LIBSYSTEM; [2]
Thread 3: Crashed
0 libsystem_kernel.dylib 0x1b80a2ae8 os_fault_with_payload + 7382641384 ((null))
1 libsystem_trace.dylib 0x000000019bd941b4 _os_log_impl_flatten_and_send + 6909673908 ((null))
2 libsystem_trace.dylib 0x000000019bd90b70 _os_log + 6909660016 ((null))
3 libsystem_trace.dylib 0x000000019bd98cac _os_log_fault_impl + 6909693100 ((null))
4 SyncedDefaults 0x1ad034c90 -[SYDRemotePreferencesSource initWithApplicationID:storeID:shared:additionalSource:containerPath:storeType:].cold.1 + 52
5 SyncedDefaults 0x1ad027210 -[SYDRemotePreferencesSource initWithApplicationID:storeID:shared:additionalSource:containerPath:storeType:] + 1400
6 Foundation 0x182ff5d58 -[NSUbiquitousKeyValueStore initWithBundleIdentifier:storeIdentifier:additionalStore:storeType:] + 348
7 Foundation 0x182fd8e84 __41+[NSUbiquitousKeyValueStore defaultStore]_block_invoke + 24
8 libdispatch.dylib 0x000000018140194c _dispatch_client_callout + 6463428940 ((null))
9 libdispatch.dylib 0x00000001814031d4 _dispatch_once_callout + 6463435220 ((null))
10 Foundation 0x182fe0668 +[NSUbiquitousKeyValueStore defaultStore] + 64
... // omit insignificant call stack of the app
14 libdispatch.dylib 0x00000001813ffc00 _dispatch_call_block_and_release + 6463421440 ((null))
15 libdispatch.dylib 0x000000018140194c _dispatch_client_callout + 6463428940 ((null))
16 libdispatch.dylib 0x0000000181413064 _dispatch_root_queue_drain + 6463500388 ((null))
17 libdispatch.dylib 0x0000000181413764 _dispatch_worker_thread2 + 6463502180 ((null))
18 libsystem_pthread.dylib 0x00000001f12c5170 _pthread_wqthread + 8341180784 ((null))
19 libsystem_pthread.dylib 0x00000001f12c4f4c start_wqthread + 8341180236 ((null))
What's mean the Exception Note: SIMULATED (this is NOT a crash)?
It's not a crash?
And then, is it possible a bug in iOS 15？because no crash reports before iOS 15.
Thanks.