I’m trying to set up a system where a quartz clock delegate queues up audio at the beginning of each bar. Unfortunately at three audio cues the whole editor crashes with a stacktrace in UnrealCore malloc calls.
Instead of pasting code, I created a repo of an example crash: playquantized_example/QuartzCrash/Source/QuartzCrash/Private at main · andriustheviking/playquantized_example · GitHub
Here’s the stack trace:
Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0xffffffffffffffff
0x00007fff907d981b UnrealEditor-Core.dll!mi_free() [D:\build\++UE5\Sync\Engine\Source\ThirdParty\mimalloc\2.0.0\src\alloc.c:486]
0x00007fff9014ea3d UnrealEditor-Core.dll!FMallocMimalloc::Realloc() [D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Private\HAL\MallocMimalloc.cpp:155]
0x00007fff9014ef33 UnrealEditor-Core.dll!FMemory::Realloc() [D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\HAL\FMemory.inl:118]
0x00007fff90013328 UnrealEditor-Core.dll!TSizedHeapAllocator<32,FMemory>::ForAnyElementType::ResizeAllocation() [D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\Containers\ContainerAllocationPolicies.h:725]
0x00007fff8b86b24c UnrealEditor-Engine.dll!TArray<TScriptDelegate<FNotThreadSafeNotCheckedDelegateMode>,TSizedDefaultAllocator<32> >::ResizeTo() [D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\Containers\Array.h:3143]
0x00007fff8b85a291 UnrealEditor-Engine.dll!FQuartzTickableObject::ExecCommand() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Classes\Sound\QuartzSubscription.cpp:122]
0x00007fff8b838c49 UnrealEditor-Engine.dll!UE::TConsumeAllMpmcQueue<TFunction<void __cdecl(FQuartzTickableObject * __ptr64)>,FMemory>::ConsumeAll<1,`Audio::TQuartzShareableCommandQueue<FQuartzTickableObject>::PumpCommandQueue'::`2'::<lambda_1> >() [D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\Containers\ConsumeAllMpmcQueue.h:119]
0x00007fff8b865bf0 UnrealEditor-Engine.dll!FQuartzTickableObject::QuartzTick() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Classes\Sound\QuartzSubscription.cpp:180]
0x00007fffac9535c4 UnrealEditor-AudioMixer.dll!FQuartzTickableObjectsManager::Tick() [D:\build\++UE5\Sync\Engine\Source\Runtime\AudioMixer\Private\Quartz\QuartzSubsystem.cpp:111]
0x00007fffac953876 UnrealEditor-AudioMixer.dll!UQuartzSubsystem::Tick() [D:\build\++UE5\Sync\Engine\Source\Runtime\AudioMixer\Private\Quartz\QuartzSubsystem.cpp:208]
0x00007fff8dbbb022 UnrealEditor-Engine.dll!FTickableGameObject::TickObjects() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\Tickable.cpp:153]
0x00007fff8ca4f681 UnrealEditor-Engine.dll!UWorld::Tick() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\LevelTick.cpp:1568]
0x00007fff8c68ad38 UnrealEditor-Engine.dll!UGameEngine::Tick() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\GameEngine.cpp:1785]
0x00007ff724ea8e0b UnrealEditor.exe!FEngineLoop::Tick() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp:5921]
0x00007ff724ece33c UnrealEditor.exe!GuardedMain() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Launch.cpp:180]
0x00007ff724ece42a UnrealEditor.exe!GuardedMainWrapper() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:118]
0x00007ff724ed18a4 UnrealEditor.exe!LaunchWindowsStartup() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:258]
0x00007ff724ee70c4 UnrealEditor.exe!WinMain() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:298]
0x00007ff724eea37a UnrealEditor.exe!__scrt_common_main_seh() [D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
0x00007ff8dacbe8d7 KERNEL32.DLL!UnknownFunction []
I don’t think it’s just an Editor issue, as I hit the following ensure in standalone:
[2025.03.26-00.34.23:632][402]LogOutputDevice: Error: === Handled ensure: ===
[2025.03.26-00.34.23:632][402]LogOutputDevice: Error:
[2025.03.26-00.34.23:632][402]LogOutputDevice: Error: Ensure condition failed: ReaderIndex != INDEX_NONE [File:D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\Misc\MTAccessDetector.h] [Line: 568]
[2025.03.26-00.34.23:632][402]LogOutputDevice: Error: Either a race detected (58240 reader(s) on another thread(s) while acquiring write access on the current thread) or the access detector was trivially relocated:
[2025.03.26-00.34.23:632][402]LogOutputDevice: Error: Current thread 10584 callstack:
[2025.03.26-00.34.23:632][402]LogOutputDevice: Error: [Callstack] 0x00007fff8b64e837 UnrealEditor-Engine.dll!FMRSWRecursiveAccessDetector::GetCurrentThreadCallstack() [D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\Misc\MTAccessDetector.h:368]
[2025.03.26-00.34.23:633][402]LogOutputDevice: Error: [Callstack] 0x00007fff8e30a3b9 UnrealEditor-Engine.dll!`FMRSWRecursiveAccessDetector::AcquireWriteAccess'::`5'::<lambda_2>::operator()() [D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\Misc\MTAccessDetector.h:568]
[2025.03.26-00.34.23:633][402]LogOutputDevice: Error: [Callstack] 0x00007fff8b645b5d UnrealEditor-Engine.dll!TDelegateAccessHandlerBase<FNotThreadSafeDelegateMode>::FWriteAccessScope::FWriteAccessScope() [D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\Delegates\DelegateAccessHandler.h:139]
[2025.03.26-00.34.23:633][402]LogOutputDevice: Error: [Callstack] 0x00007fff8b85a27c UnrealEditor-Engine.dll!FQuartzTickableObject::ExecCommand() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Classes\Sound\QuartzSubscription.cpp:122]
[2025.03.26-00.34.23:633][402]LogOutputDevice: Error: [Callstack] 0x00007fff8b838c49 UnrealEditor-Engine.dll!UE::TConsumeAllMpmcQueue<TFunction<void __cdecl(FQuartzTickableObject * __ptr64)>,FMemory>::ConsumeAll<1,`Audio::TQuartzShareableCommandQueue<FQuartzTickableObject>::PumpCommandQueue'::`2'::<lambda_1> >() [D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\Containers\ConsumeAllMpmcQueue.h:119]
[2025.03.26-00.34.23:633][402]LogOutputDevice: Error: [Callstack] 0x00007fff8b865bf0 UnrealEditor-Engine.dll!FQuartzTickableObject::QuartzTick() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Classes\Sound\QuartzSubscription.cpp:180]
[2025.03.26-00.34.23:633][402]LogOutputDevice: Error: [Callstack] 0x00007fffac9535c4 UnrealEditor-AudioMixer.dll!FQuartzTickableObjectsManager::Tick() [D:\build\++UE5\Sync\Engine\Source\Runtime\AudioMixer\Private\Quartz\QuartzSubsystem.cpp:111]
[2025.03.26-00.34.23:633][402]LogOutputDevice: Error: [Callstack] 0x00007fffac953876 UnrealEditor-AudioMixer.dll!UQuartzSubsystem::Tick() [D:\build\++UE5\Sync\Engine\Source\Runtime\AudioMixer\Private\Quartz\QuartzSubsystem.cpp:208]
[2025.03.26-00.34.23:633][402]LogOutputDevice: Error: [Callstack] 0x00007fff8dbbb022 UnrealEditor-Engine.dll!FTickableGameObject::TickObjects() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\Tickable.cpp:153]
[2025.03.26-00.34.23:633][402]LogOutputDevice: Error: [Callstack] 0x00007fff8ca4f681 UnrealEditor-Engine.dll!UWorld::Tick() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\LevelTick.cpp:1568]
[2025.03.26-00.34.23:633][402]LogOutputDevice: Error: [Callstack] 0x00007fff8c68ad38 UnrealEditor-Engine.dll!UGameEngine::Tick() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\GameEngine.cpp:1785]
[2025.03.26-00.34.23:633][402]LogOutputDevice: Error: [Callstack] 0x00007ff724ea8e0b UnrealEditor.exe!FEngineLoop::Tick() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp:5921]
[2025.03.26-00.34.23:633][402]LogOutputDevice: Error: [Callstack] 0x00007ff724ece33c UnrealEditor.exe!GuardedMain() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Launch.cpp:180]
[2025.03.26-00.34.23:633][402]LogOutputDevice: Error: [Callstack] 0x00007ff724ece42a UnrealEditor.exe!GuardedMainWrapper() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:118]
[2025.03.26-00.34.23:633][402]LogOutputDevice: Error: [Callstack] 0x00007ff724ed18a4 UnrealEditor.exe!LaunchWindowsStartup() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:258]
[2025.03.26-00.34.23:633][402]LogOutputDevice: Error: [Callstack] 0x00007ff724ee70c4 UnrealEditor.exe!WinMain() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:298]
[2025.03.26-00.34.23:633][402]LogOutputDevice: Error: [Callstack] 0x00007ff724eea37a UnrealEditor.exe!__scrt_common_main_seh() [D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
[2025.03.26-00.34.23:633][402]LogOutputDevice: Error: [Callstack] 0x00007ff8dacbe8d7 KERNEL32.DLL!UnknownFunction []
[2025.03.26-00.34.23:633][402]LogOutputDevice: Error: [Callstack] 0x00007ff8dbb3bf6c ntdll.dll!UnknownFunction []
[2025.03.26-00.34.23:634][402]LogOutputDevice: Error:
[2025.03.26-00.34.23:634][402]LogOutputDevice: Error: Stack:
[2025.03.26-00.34.23:634][402]LogOutputDevice: Error: [Callstack] 0x00007fff8e30a404 UnrealEditor-Engine.dll!`FMRSWRecursiveAccessDetector::AcquireWriteAccess'::`5'::<lambda_2>::operator()() [D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\Misc\MTAccessDetector.h:568]
[2025.03.26-00.34.23:634][402]LogOutputDevice: Error: [Callstack] 0x00007fff8b645b5d UnrealEditor-Engine.dll!TDelegateAccessHandlerBase<FNotThreadSafeDelegateMode>::FWriteAccessScope::FWriteAccessScope() [D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\Delegates\DelegateAccessHandler.h:139]
[2025.03.26-00.34.23:634][402]LogOutputDevice: Error: [Callstack] 0x00007fff8b85a27c UnrealEditor-Engine.dll!FQuartzTickableObject::ExecCommand() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Classes\Sound\QuartzSubscription.cpp:122]
[2025.03.26-00.34.23:634][402]LogOutputDevice: Error: [Callstack] 0x00007fff8b838c49 UnrealEditor-Engine.dll!UE::TConsumeAllMpmcQueue<TFunction<void __cdecl(FQuartzTickableObject * __ptr64)>,FMemory>::ConsumeAll<1,`Audio::TQuartzShareableCommandQueue<FQuartzTickableObject>::PumpCommandQueue'::`2'::<lambda_1> >() [D:\build\++UE5\Sync\Engine\Source\Runtime\Core\Public\Containers\ConsumeAllMpmcQueue.h:119]
[2025.03.26-00.34.23:634][402]LogOutputDevice: Error: [Callstack] 0x00007fff8b865bf0 UnrealEditor-Engine.dll!FQuartzTickableObject::QuartzTick() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Classes\Sound\QuartzSubscription.cpp:180]
[2025.03.26-00.34.23:634][402]LogOutputDevice: Error: [Callstack] 0x00007fffac9535c4 UnrealEditor-AudioMixer.dll!FQuartzTickableObjectsManager::Tick() [D:\build\++UE5\Sync\Engine\Source\Runtime\AudioMixer\Private\Quartz\QuartzSubsystem.cpp:111]
[2025.03.26-00.34.23:634][402]LogOutputDevice: Error: [Callstack] 0x00007fffac953876 UnrealEditor-AudioMixer.dll!UQuartzSubsystem::Tick() [D:\build\++UE5\Sync\Engine\Source\Runtime\AudioMixer\Private\Quartz\QuartzSubsystem.cpp:208]
[2025.03.26-00.34.23:634][402]LogOutputDevice: Error: [Callstack] 0x00007fff8dbbb022 UnrealEditor-Engine.dll!FTickableGameObject::TickObjects() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\Tickable.cpp:153]
[2025.03.26-00.34.23:634][402]LogOutputDevice: Error: [Callstack] 0x00007fff8ca4f681 UnrealEditor-Engine.dll!UWorld::Tick() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\LevelTick.cpp:1568]
[2025.03.26-00.34.23:634][402]LogOutputDevice: Error: [Callstack] 0x00007fff8c68ad38 UnrealEditor-Engine.dll!UGameEngine::Tick() [D:\build\++UE5\Sync\Engine\Source\Runtime\Engine\Private\GameEngine.cpp:1785]
[2025.03.26-00.34.23:634][402]LogOutputDevice: Error: [Callstack] 0x00007ff724ea8e0b UnrealEditor.exe!FEngineLoop::Tick() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp:5921]
[2025.03.26-00.34.23:634][402]LogOutputDevice: Error: [Callstack] 0x00007ff724ece33c UnrealEditor.exe!GuardedMain() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Launch.cpp:180]
[2025.03.26-00.34.23:634][402]LogOutputDevice: Error: [Callstack] 0x00007ff724ece42a UnrealEditor.exe!GuardedMainWrapper() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:118]
[2025.03.26-00.34.23:634][402]LogOutputDevice: Error: [Callstack] 0x00007ff724ed18a4 UnrealEditor.exe!LaunchWindowsStartup() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:258]
[2025.03.26-00.34.23:634][402]LogOutputDevice: Error: [Callstack] 0x00007ff724ee70c4 UnrealEditor.exe!WinMain() [D:\build\++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:298]
[2025.03.26-00.34.23:634][402]LogOutputDevice: Error: [Callstack] 0x00007ff724eea37a UnrealEditor.exe!__scrt_common_main_seh() [D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
[2025.03.26-00.34.23:634][402]LogOutputDevice: Error: [Callstack] 0x00007ff8dacbe8d7 KERNEL32.DLL!UnknownFunction []
[2025.03.26-00.34.23:634][402]LogOutputDevice: Error: [Callstack] 0x00007ff8dbb3bf6c ntdll.dll!UnknownFunction []