SystemSettings.exe AppHang during Airplane Mode Toggle Stress Test

Question

Product: Windows 11, version 25H2

Category: System Performance

Description:

[Issue Summary] During system stress testing using an automated tool—specifically targeting the Airplane Mode / Wi-Fi toggle—we observed that the Windows Settings app (SystemSettings.exe) intermittently hangs and becomes unresponsive. This issue blocks the testing process from completing successfully.

[Technical Details]

• Hanging Process: SystemSettings.exe
• Symptom: Application Hang
• Call Stack Observation: The thread appears to be stuck at ntdll!NtWaitForMultipleObjects. We need Microsoft's assistance to analyze what OS event or underlying API the Settings app is waiting for.

[Attachments]

Hang DMP：

FILE_IN_CAB:  SystemSettings.DMP

 

NTGLOBALFLAG:  0

 

APPLICATION_VERIFIER_FLAGS:  0

 

CONTEXT:  (.cxr;r)

rax=000000000000005b rbx=0000000000000002 rcx=0000000000000002

rdx=00000032a3dff2b0 rsi=0000000000000000 rdi=0000000000000002

rip=00007ffa71b225b4 rsp=00000032a3dfef68 rbp=0000000000000000

r8=0000000000000001  r9=0000000000000000 r10=0000000000000002

r11=0000000000000002 r12=00000032a3dff2b0 r13=00000032a3af6000

r14=0000000000000000 r15=0000000000000000

iopl=0         nv up ei pl zr na po nc

cs=0033  ss=002b  ds=002b  es=002b  fs=0053  gs=002b             efl=00000246

ntdll!NtWaitForMultipleObjects+0x14:

00007ffa`71b225b4 c3              ret

 

EXCEPTION_RECORD:  (.exr -1)

ExceptionAddress: 0000000000000000

   ExceptionCode: 80000003 (Break instruction exception)

  ExceptionFlags: 00000000

NumberParameters: 0

 

FAULTING_THREAD:  3748

 

PROCESS_NAME:  SystemSettings.exe

 

WATSON_BKT_EVENT:  AppHang

 

BLOCKING_THREAD:  3748

 

ERROR_CODE: (NTSTATUS) 0xcfffffff - <Unable to get error code text>

 

EXCEPTION_CODE_STR:  cfffffff

 

DERIVED_WAIT_CHAIN: 

 

Dl Eid Cid     WaitType

---

   0   3524.3748 Unknown               

 

WAIT_CHAIN_COMMAND:  ~0s;k;;

 

STACK_TEXT: 

00000032a3dfef68 00007ffa6f391a93     : 0000000000000000 0000000000000000 00007ffa71873358 0000000000000000 : ntdll!NtWaitForMultipleObjects+0x14

00000032a3dfef70 00007ffa5b5b35e9     : 0000000000000774 0000000000000000 0000000000000774 00000000ffffffff : KERNELBASE!WaitForMultipleObjectsEx+0x123

00000032a3dff260 00007ffa5b5b3076     : 0000000200000037 0000000000000000 00000032a3dff579 000001b9fd13a0b0 : twinapi_appcore!Event::WaitWithFreeUnusedLibraries+0xd1

00000032a3dff4e0 00007ffa5b5b302c     : 00000032a3dff650 00007ffa5b7215a0 0000000000000000 00007ffa5b5b1908 : twinapi_appcore!Windows::ApplicationModel::Core::CoreApplication::WaitForExit+0x16

00000032a3dff510 00007ffa5b5b2a1c     : 000001b9fd1179a0 0000000000000000 0000000000000001 0000000000000000 : twinapi_appcore!<lambda_bfab231890c320cd8323e9510fdb48c6>::operator()+0x204

00000032a3dff5e0 00007ffa5b597353     : 0000000000000000 000001b9fd14d870 0000000000000000 000001b9fd14fc00 : twinapi_appcore!Windows::ApplicationModel::Core::CoreApplication::RunInternal+0x128

00000032a3dff7f0 00007ffa512cbc67     : 0000000000000000 00000032a3dff890 000001b9fd13a0b0 00007ffa5152c79a : twinapi_appcore!Windows::ApplicationModel::Core::CoreApplicationFactory::Run+0x83

00000032a3dff830 00007ffa5152c716     : 000001b9fd137700 00007ff9eaac7450 000061a240848adc 0000000000000000 : Windows_UI_Xaml!RunInActivationMode+0xb7

00000032a3dff8a0 00007ff9ea6a7cf8     : 0000000000000000 0000000000000000 0000000000850940 0000000000000000 : Windows_UI_Xaml!DirectUI::FrameworkApplicationFactory::Start+0x26

00000032a3dff8d0 00007ff9ea6e5b3f     : 0000000000000000 00007ff9ea680000 0000000000000130 000001b9fd137700 : SystemSettings!SystemSettings::ViewModel::IGroupableSettingBase::ReleaseHandlers+0x10

00000032a3dff900 00007ff9ea6e57b9     : 000001b9fd137728 000001b9fd137700 0000000000000000 00007ffa6f3a2fa2 : SystemSettings!Windows::UI::Xaml::Application::Start+0x6b

00000032a3dff950 00007ff7b621abc0     : 00000032a3dffa19 00007ff9ea73ab80 0000000000000000 0000000000000000 : SystemSettings!StartSystemSettingsApplication+0xd1

00000032a3dff9e0 00007ff7b6211fd6     : 0000000000000001 0000000000000000 000000000000001f 0000000000000000 : SystemSettings_exe!wWinMain+0x288

00000032a3dffa80 00007ffa7067e8d7     : 0000000000000000 0000000000000000 0000000000000000 0000000000000000 : SystemSettings_exe!__wmainCRTStartup+0x1d6

00000032a3dffb40 00007ffa71a4c3fc     : 0000000000000000 0000000000000000 000004f0fffffb30 000004d0fffffb30 : kernel32!BaseThreadInitThunk+0x17

00000032a3dffb70 0000000000000000     : 0000000000000000 0000000000000000 0000000000000000 0000000000000000 : ntdll!RtlUserThreadStart+0x2c

 

 

STACK_COMMAND: ~0s; .ecxr ; kb

 

SYMBOL_NAME:  twinapi_appcore!Event::WaitWithFreeUnusedLibraries+d1

 

MODULE_NAME: twinapi_appcore

 

IMAGE_NAME:  twinapi.appcore.dll

 

FAILURE_BUCKET_ID:  APPLICATION_HANG_cfffffff_twinapi.appcore.dll!Event::WaitWithFreeUnusedLibraries

 

OS_VERSION:  10.0.26100.2

 

BUILDLAB_STR:  ge_release_flt

 

OSPLATFORM_TYPE:  x64

 

OSNAME:  Windows 10

 

IMAGE_VERSION:  10.0.26100.8079

 

FAILURE_ID_HASH:  {f1f2cbca-c534-d8f7-1416-f48e5d4e68d2}

 

Followup:     MachineOwner

Answer 1

The hang dump and stack trace indicate an AppHang (Watson bucket type AppHang) in SystemSettings.exe where the main thread is blocked in a generic wait, surfaced as:

• ntdll!NtWaitForMultipleObjects
• KERNELBASE!WaitForMultipleObjectsEx
• twinapi_appcore!Event::WaitWithFreeUnusedLibraries
• twinapi_appcore!Windows::ApplicationModel::Core::CoreApplication::WaitForExit

This pattern matches a generic application hang captured by Windows Hang Reporting. The event is surfaced through the Microsoft.Windows.HangReporting.AppHangEvent telemetry, which records:

• AppName = SystemSettings.exe
• ProcessId of the hung Settings process
• ReportId and TargetAsId to correlate the hang with the Watson report
• TypeCode describing the hang type

From the available data, the OS-level view is that the Settings app is blocked in the WinRT app core wait loop (CoreApplication::WaitForExit) via twinapi_appcore!Event::WaitWithFreeUnusedLibraries, which internally uses NtWaitForMultipleObjects to wait on one or more kernel objects (for example, events or handles owned by the app framework). The hang-reporting pipeline does not expose which specific handle or OS event is being waited on; it only records that the process is not making forward progress and classifies it as an AppHang.

For automated Airplane Mode / Wi‑Fi toggle stress tests, this means:

1. The Settings app is a UWP/XAML application whose main thread is stuck in the WinRT app core wait loop, not in a specific public OS API that can be directly controlled from outside.
2. The OS telemetry and hang reporting (via Microsoft.Windows.HangReporting.AppHangEvent) can be used to correlate and analyze frequency and conditions of the hang, but they do not reveal the exact internal event or handle that SystemSettings.exe is waiting on.
3. The hang is therefore treated as an application-level responsiveness issue in SystemSettings.exe under the exercised scenario (rapid Airplane Mode / Wi‑Fi toggling), rather than a directly diagnosable kernel wait on a documented external API.

To proceed with deeper analysis or a potential fix, the hang dump, Watson AppHang reports (using the ReportId and TargetAsId fields), and the exact stress-test conditions would need to be provided to Microsoft Support or engineering through official support channels so that internal symbols and additional telemetry can be used to determine the precise internal wait condition.

---

References:

• Windows 11, versions 25H2 and 24H2 required diagnostic data events and fields