# Cook error in 5.7.1

**URL:** <https://community.cesium.com/t/cook-error-in-5-7-1/44771>\
**Category:** Cesium for Unreal\
**Created:** [January 6, 2026, 5:22pm UTC](https://community.cesium.com/t/cook-error-in-5-7-1/44771 "2026-01-06T17:22:39Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![flav](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/flav/32/21649_2.png) [@flav](https://community.cesium.com/u/flav)\
**Post date:** [January 6, 2026, 5:22pm UTC](https://community.cesium.com/t/cook-error-in-5-7-1/44771/1 "2026-01-06T17:22:39Z")

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Anyone seen this before? The error triggers when trying to package a project in UE 5.7.1. This project was just upgraded from 5.4.4 where it had no troubles cooking.

> UATHelper: Error: Packaging (Windows): LogWindows: Error: begin: stack for UAT  
> UATHelper: Error: Packaging (Windows): LogWindows: Error: === Critical error: ===  
> UATHelper: Error: Packaging (Windows): LogWindows: Error:  
> UATHelper: Error: Packaging (Windows): LogWindows: Error: Fatal error!  
> UATHelper: Error: Packaging (Windows): LogWindows: Error:  
> UATHelper: Error: Packaging (Windows): LogWindows: Error: Unhandled Exception: EXCEPTION\_ACCESS\_VIOLATION reading address 0xffffffffffffffff  
> UATHelper: Error: Packaging (Windows): LogWindows: Error:  
> UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffa0eaf31a1 UnrealEditor-CesiumRuntime.dll!Cesium3DTilesSelection::TilesetContentLoader::setOwner()   
> UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffa0eaf387a UnrealEditor-CesiumRuntime.dll!async::detail::task\_func\<async::detail::inline\_scheduler\_impl,async::detail::continuation\_exec\_func\<async::detail::inline\_scheduler\_impl,async::taskCesium3DTilesSelection::TileLoadResult,std::tupleCesium3DTilesSelection::TileContentLoadInfo,Cesium3DTilesSelection::TileLoadResult,`CesiumAsync::Future<Cesium3DTilesSelection::TileLoadResult>::thenPassThrough<Cesium3DTilesSelection::TileContentLoadInfo>'::`2’::\<lambda\_1\>,std::integral\_constant\<bool,1\>,0\>,std::tuple\<Cesium3DTi  
> lesSelection::TileContentLoadInfo,Cesium3DTilesSelection::TileLoadResult\> \>::destroy()   
> UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffa0eb4a8ce UnrealEditor-CesiumRuntime.dll!CesiumAsync::CesiumImpl::QueuedScheduler::dispatchInternal()   
> UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffa0eb4a97a UnrealEditor-CesiumRuntime.dll!CesiumAsync::CesiumImpl::QueuedScheduler::dispatchQueuedContinuations()   
> UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffa0e1fcce1 UnrealEditor-CesiumRuntime.dll!ACesium3DTileset::IsReadyForFinishDestroy() [E:\project\Plugins\CesiumForUnreal\Source\CesiumRuntime\Private\Cesium3DTileset.cpp:2363]  
> UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffa8b1dff03 UnrealEditor-CoreUObject.dll!IncrementalDestroyGarbage() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\GarbageCollection.cpp:4836]  
> UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffa8b1e0961 UnrealEditor-CoreUObject.dll!IncrementalPurgeGarbage() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\GarbageCollection.cpp:4721]  
> UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffa8b1647b6 UnrealEditor-CoreUObject.dll!UE::GC::PostCollectGarbageImpl\<1\>() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\GarbageCollection.cpp:5778]  
> UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffa8b1e663d UnrealEditor-CoreUObject.dll!UE::GC::FReachabilityAnalysisState::PerformReachabilityAnalysisAndConditionallyPurgeGarbage() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\GarbageCollection.cpp:5970]  
> UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffa8b19a063 UnrealEditor-CoreUObject.dll!CollectGarbage() [D:\build++UE5\Sync\Engine\Source\Runtime\CoreUObject\Private\UObject\GarbageCollection.cpp:6216]  
> UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffa2d57cd41 UnrealEditor-UnrealEd.dll!UCookCommandlet::ConditionalCollectGarbage() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\Commandlets\CookCommandlet.cpp:756]  
> UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffa2d5ba10a UnrealEditor-UnrealEd.dll!UCookCommandlet::RunCookByTheBookCook() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\Commandlets\CookCommandlet.cpp:603]  
> UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffa2d57f11a UnrealEditor-UnrealEd.dll!UCookCommandlet::CookByTheBook() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\Commandlets\CookCommandlet.cpp:559]  
> UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffa2d59f723 UnrealEditor-UnrealEd.dll!UCookCommandlet::Main() [D:\build++UE5\Sync\Engine\Source\Editor\UnrealEd\Private\Commandlets\CookCommandlet.cpp:278]  
> UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ff6eb34a5c1 UnrealEditor-Cmd.exe!FEngineLoop::PreInitPostStartupScreen() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\LaunchEngineLoop.cpp:4053]  
> UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ff6eb340a1b UnrealEditor-Cmd.exe!GuardedMain() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Launch.cpp:146]  
> UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ff6eb340d0a UnrealEditor-Cmd.exe!GuardedMainWrapper() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:123]  
> UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ff6eb344590 UnrealEditor-Cmd.exe!LaunchWindowsStartup() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:277]  
> UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ff6eb355bd4 UnrealEditor-Cmd.exe!WinMain() [D:\build++UE5\Sync\Engine\Source\Runtime\Launch\Private\Windows\LaunchWindows.cpp:334]  
> UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ff6eb3582e6 UnrealEditor-Cmd.exe!\_\_scrt\_common\_main\_seh() [D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe\_common.inl:288]  
> UATHelper: Error: Packaging (Windows): LogWindows: Error: [Callstack] 0x00007ffc01e8e8d7 KERNEL32.DLL!UnknownFunction   
> UATHelper: Error: Packaging (Windows): LogWindows: Error:  
> UATHelper: Error: Packaging (Windows): LogWindows: Error: end: stack for UAT  
> UATHelper: Error: Packaging (Windows): Took 49.35s to run UnrealEditor-Cmd.exe, ExitCode=3  
> UATHelper: Error: Packaging (Windows): Cook failed.

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<div class="post-metadata">

**Author:** ![flav](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/flav/32/21649_2.png) [@flav](https://community.cesium.com/u/flav)\
**Post date:** [January 6, 2026, 5:26pm UTC](https://community.cesium.com/t/cook-error-in-5-7-1/44771/2 "2026-01-06T17:26:55Z")

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I should note, this is using the Cesium plugin released today (Jan 6).

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**Author:** ![Kevin\_Ring](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/kevin_ring/32/2003_2.png) [@Kevin\_Ring](https://community.cesium.com/u/Kevin_Ring)\
**Post date:** [January 8, 2026, 5:02am UTC](https://community.cesium.com/t/cook-error-in-5-7-1/44771/3 "2026-01-08T05:02:04Z")

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Hi @flav,

Sorry you’re having trouble. Can you please check if the Cesium for Unreal Samples project packages successfully? That may help narrow down where the problem lies.

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<div class="post-metadata">

**Author:** ![flav](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/flav/32/21649_2.png) [@flav](https://community.cesium.com/u/flav)\
**Post date:** [January 12, 2026, 5:40pm UTC](https://community.cesium.com/t/cook-error-in-5-7-1/44771/4 "2026-01-12T17:40:07Z")

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Hey @Kevin_Ring ,

The sample project packages fine, but it obviously doesn’t have the same actors in the world, so it doesn’t help much. I’m trying to narrow down what specific actor/asset might be causing it. But let’s say I find the 3dtile that’s causing the cook error, what would be the next step to make progress?

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<div class="post-metadata">

**Author:** ![flav](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/flav/32/21649_2.png) [@flav](https://community.cesium.com/u/flav)\
**Post date:** [January 12, 2026, 6:30pm UTC](https://community.cesium.com/t/cook-error-in-5-7-1/44771/5 "2026-01-12T18:30:46Z")

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@Kevin_Ring I managed to get a repro in the cesium sample project.

1. create a project form the Cesium Sample
2. add a new blank tileset
3. set source to ellipsoid
4. add the imagery (id 2) to it (unsure if this is needed)
5. package Development for Windows

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<div class="post-metadata">

**Author:** ![flav](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/flav/32/21649_2.png) [@flav](https://community.cesium.com/u/flav)\
**Post date:** [January 22, 2026, 7:07pm UTC](https://community.cesium.com/t/cook-error-in-5-7-1/44771/6 "2026-01-22T19:07:13Z")

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@Kevin_Ring The fix from github worked, but I’m now hitting something else that may be related, though I’ll admit I’m just guessing for now. what’s worse, it only happens on linux. On windows things seem fine, but on linux very quick after boot I get the crash below, curious if you’re seeing the same.

> App!Cesium3DTilesSelection::Tile::~Tile()  
> App!async::detail::task\_func\<CesiumAsync::CesiumImpl::ImmediateSchedulerCesiumAsync::CesiumImpl::QueuedScheduler, async::detail::continuation\_exec\_func\<CesiumAsync::CesiumImpl::ImmediateSchedulerCesiumAsync::CesiumImpl::QueuedScheduler, async::task, async::detail::fake\_void, Cesium3DTilesSelection::TilesetContentManager::TilesetContentManager(Cesium3DTilesSelection::TilesetExternals const&, Cesium3DTilesSelection::TilesetOptions const&, std::\_\_1::unique\_ptr\<Cesium3DTilesSelection::TilesetContentLoader, std::\_\_1::default\_deleteCesium3DTilesSelection::TilesetContentLoader \>&&, std::\_\_1::unique\_ptr\<Cesium3DTilesSelection::Tile, std::\_\_1::default\_deleteCesium3DTilesSelection::Tile \>&&)::$\_0, std::\_\_1::integral\_constant\<bool, true\>, false\>, async::detail::fake\_void\>::run(async::detail::task\_base\*)  
> App!CesiumAsync::CesiumImpl::QueuedScheduler::dispatchInternal(bool)  
> App!CesiumAsync::CesiumImpl::QueuedScheduler::dispatchQueuedContinuations()  
> App!Cesium3DTilesSelection::Tileset::updateViewGroup(Cesium3DTilesSelection::TilesetViewGroup&, std::\_\_1::vector\<Cesium3DTilesSelection::ViewState, std::\_\_1::allocatorCesium3DTilesSelection::ViewState \> const&, float)  
> App!ACesium3DTileset::Tick(float)  
> App!FActorTickFunction::ExecuteTick(float, ELevelTick, ENamedThreads::Type, TRefCountPtr const&)  
> App!FTickFunctionTask::DoTask(ENamedThreads::Type, TRefCountPtr const&)  
> App!TGraphTask::ExecuteTask()  
> App!UE::Tasks::Private::FTaskBase::TryExecuteTask()  
> App!FNamedTaskThread::ProcessTasksNamedThread(int, bool)  
> App!FNamedTaskThread::ProcessTasksUntilIdle(int)  
> App!FTaskGraphCompatibilityImplementation::ProcessUntilTasksComplete(TArray\<TRefCountPtr, TSizedInlineAllocator\<4u, 32, TSizedDefaultAllocator\<32\> \> \> const&, ENamedThreads::Type, TFunction\<FTaskGraphInterface::EProcessTasksOperation (int)\> const&)  
> App!FTickTaskSequencer::ReleaseTickGroup(ETickingGroup, bool, TArray\<FTickFunction\*, TSizedDefaultAllocator\<32\> \>&)  
> App!FTickTaskManager::RunTickGroup(ETickingGroup, bool)  
> App!UWorld::Tick(ELevelTick, float)  
> App!UGameEngine::Tick(float, bool)  
> App!FEngineLoop::Tick()  
> App!GuardedMain(char16\_t const\*)  
> App!CommonUnixMain(int, char\*\*, int (_)(char16\_t const_), void (\*)())  
> libc.so.6!UnknownFunction(0x2a1c9)  
> libc.so.6!\_\_libc\_start\_main(+0x8a)

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<div class="post-metadata">

**Author:** ![janine](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/janine/32/5135_2.png) [@janine](https://community.cesium.com/u/janine)\
**Post date:** [January 23, 2026, 3:50pm UTC](https://community.cesium.com/t/cook-error-in-5-7-1/44771/7 "2026-01-23T15:50:50Z")

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Sorry that you’re still seeing issues @flav!

Just to confirm, are you seeing this crash with the repro steps you shared in your previous comment? Or is this from something else?

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<div class="post-metadata">

**Author:** ![flav](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/flav/32/21649_2.png) [@flav](https://community.cesium.com/u/flav)\
**Post date:** [January 23, 2026, 4:15pm UTC](https://community.cesium.com/t/cook-error-in-5-7-1/44771/8 "2026-01-23T16:15:06Z")

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hey @janine , i haven’t verified in the tiny sample project if it repros there too, this happens in our main project. but there’s a chance i got past it, though i’m not entirely sure why or how. i’m currently using native libraries from the github branch with that fix, and i could have sworn i downloaded the main package that includes all the platforms. but then i got the linux specific package and making a new build with that seems to have fixed the crash on linux for now. i’m not sure why. i guess there’s a chance i only got the windows binaries when i first tried the fix.