#3 crash for 91.3.0. No version 78 crash reports.

Majority of crash sampled do NOT have AV software in modules list.

Crash report: https://crash-stats.mozilla.org/report/index/af53fa32-1448-4b81-9603-0ce000211109

MOZ_CRASH Reason: MOZ_CRASH(Shutdown hanging after all known phases and workers finished.)

Top 10 frames of crashing thread:

0 ntdll.dll NtWaitForAlertByThreadId 
1 ntdll.dll RtlSleepConditionVariableSRW 
2 KERNELBASE.dll SleepConditionVariableSRW 
3 mozglue.dll mozilla::detail::ConditionVariableImpl::wait mozglue/misc/ConditionVariable_windows.cpp:50
4 xul.dll mozilla::TaskController::GetRunnableForMTTask xpcom/threads/TaskController.cpp:544
5 xul.dll nsThread::ProcessNextEvent xpcom/threads/nsThread.cpp:1086
6 xul.dll NS_ProcessNextEvent xpcom/threads/nsThreadUtils.cpp:466
7 xul.dll nsThread::Shutdown xpcom/threads/nsThread.cpp:844
8 xul.dll nsThreadManager::Shutdown xpcom/threads/nsThreadManager.cpp:412
9 xul.dll mozilla::ShutdownXPCOM xpcom/build/XPCOMInit.cpp:655

beta 95 bp-48bcd8c8-eae0-4877-9e5c-c07530211109

Windows 8.1 , 64 bit
TB (91.9.0 (32-Bit))

After PC was locked via Screensaver TB crashed while closing TB.

Thunderbird 91.9.0 Crash Report
[@ shutdownhang | mozilla::TaskController::GetRunnableForMTTask | nsThread::Shutdown | nsThreadManager::Shutdown ]
bp-e7e693ce-05a9-4811-a891-991fc0220518

Crashing Thread (0)
Frame Module Signature Source Trust
0 ntdll.dll NtWaitForAlertByThreadId context
1 ntdll.dll RtlSleepConditionVariableSRW cfi
2 KERNELBASE.dll SleepConditionVariableSRW cfi
3 mozglue.dll mozilla::detail::ConditionVariableImpl::wait(mozilla::detail::MutexImpl&) mozglue/misc/ConditionVariable_windows.cpp:50 cfi
4 xul.dll mozilla::TaskController::GetRunnableForMTTask(bool) xpcom/threads/TaskController.cpp:544 cfi
5 xul.dll nsThread::ProcessNextEvent(bool, bool*) xpcom/threads/nsThread.cpp:1086 cfi
6 xul.dll NS_ProcessNextEvent(nsIThread*, bool) xpcom/threads/nsThreadUtils.cpp:466 cfi
7 xul.dll nsThread::Shutdown() xpcom/threads/nsThread.cpp:844 cfi
8 xul.dll nsThreadManager::Shutdown() xpcom/threads/nsThreadManager.cpp:412 cfi
9 xul.dll mozilla::ShutdownXPCOM(nsIServiceManager*) xpcom/build/XPCOMInit.cpp:655 cfi
10 xul.dll ScopedXPCOMStartup::~ScopedXPCOMStartup() toolkit/xre/nsAppRunner.cpp:1681 cfi
11 xul.dll mozilla::UniquePtr<ScopedXPCOMStartup, mozilla::DefaultDelete<ScopedXPCOMStartup> >::reset(ScopedXPCOMStartup*) mfbt/UniquePtr.h:305 cfi
12 xul.dll XREMain::XRE_main(int, char**, mozilla::BootstrapConfig const&) toolkit/xre/nsAppRunner.cpp:5451 cfi
13 xul.dll XRE_main(int, char**, mozilla::BootstrapConfig const&) toolkit/xre/nsAppRunner.cpp:5493 cfi
14 xul.dll mozilla::BootstrapImpl::XRE_main(int, char**, mozilla::BootstrapConfig const&) toolkit/xre/Bootstrap.cpp:45 cfi
15 thunderbird.exe NS_internal_main(int, char**, char**) mail/app/nsMailApp.cpp:368 cfi
16 thunderbird.exe wmain(int, wchar_t**) toolkit/xre/nsWindowsWMain.cpp:131 cfi
17 thunderbird.exe __scrt_common_main_seh() /builds/worker/workspace/obj-build/comm/mail/app/f:/dd/vctools/crt/vcstartup/src/startup/exe_common.inl:288 cfi
18 kernel32.dll BaseThreadInitThunk cfi
19 ntdll.dll _RtlUserThreadStart cfi
20 ntdll.dll _RtlUserThreadStart cfi

It looks like in version 102 the crash signature is [@ shutdownhang | mozilla::TaskController::GetRunnableForMTTask | nsThread::Shutdown | nsThreadManager::ShutdownNonMainThreads ] which is the #2 crash for 102.0
bp-f484d2b3-040f-4243-b325-fbee60220707
0 ntdll.dll NtWaitForAlertByThreadId
1 ntdll.dll RtlSleepConditionVariableSRW
2 KERNELBASE.dll SleepConditionVariableSRW
3 mozglue.dll mozilla::detail::ConditionVariableImpl::wait(mozilla::detail::MutexImpl&) mozglue/misc/ConditionVariable_windows.cpp:50
4 xul.dll mozilla::TaskController::GetRunnableForMTTask(bool) xpcom/threads/TaskController.cpp:523
5 xul.dll nsThread::ProcessNextEvent(bool, bool*) xpcom/threads/nsThread.cpp:1114
6 xul.dll NS_ProcessNextEvent(nsIThread*, bool) xpcom/threads/nsThreadUtils.cpp:465

Since I can easily repro bug 1768344 (similar-ish to this bug), let me know if I can help troubleshoot.

bp-98246621-dc76-43f1-bdee-d761f0220810 restarting nightly for an update

This looks like a duplicate of bug 1505660, Wayne shall we just dup against that one? Note that after my changes to bug 1794587 the crash signatures here will join those in bug 1505660 because the stacks are the same.

Thanks. Let's make it a blocker