Cesium crashing Linux Multiplayer Server

Cesium for Unreal
1

I am using Cesium in a multiplayer map that uses Cesium and it crashes with this stack. Any ideas why this may happen or how to fix it?

Thank you,

-Brandon

[2025.02.28-03.57.38:494][401]LogLoad: Took 1.142653 seconds to LoadMap(/RedRocks2025/Levels/RedRocks_Primary)
[2025.02.28-03.57.38:494][401]LogGlobalStatus: LoadMap Load map complete /RedRocks2025/Levels/RedRocks_Primary
[2025.02.28-03.57.38:615][404]LogCore: === Critical error: ===
Unhandled Exception: SIGSEGV: invalid attempt to read memory at address 0x0000000000010008

[2025.02.28-03.57.38:615][404]LogCore: Fatal error!

0x00000000106a6833 VirtuosoServer!rapidjson::GenericValue<rapidjson::UTF8, rapidjson::MemoryPoolAllocatorrapidjson::CrtAllocator >::SetStringRaw(rapidjson::GenericStringRef, rapidjson::MemoryPoolAllocatorrapidjson::CrtAllocator&)(+0x63)
0x00000000106a6125 VirtuosoServer!rapidjson::GenericDocument<rapidjson::UTF8, rapidjson::MemoryPoolAllocatorrapidjson::CrtAllocator, rapidjson::CrtAllocator>::String(char const*, unsigned int, bool)()
0x000000001077ef26 VirtuosoServer!void rapidjson::GenericReader<rapidjson::UTF8, rapidjson::UTF8, rapidjson::CrtAllocator>::ParseString<0u, rapidjson::EncodedInputStream<rapidjson::UTF8, rapidjson::MemoryStream>, rapidjson::GenericDocument<rapidjson::UTF8, rapidjson::MemoryPoolAllocatorrapidjson::CrtAllocator, rapidjson::CrtAllocator> >(rapidjson::EncodedInputStream<rapidjson::UTF8, rapidjson::MemoryStream>&, rapidjson::GenericDocument<rapidjson::UTF8, rapidjson::MemoryPoolAllocatorrapidjson::CrtAllocator, rapidjson::CrtAllocator>&, bool)()
0x000000001077f158 VirtuosoServer!void rapidjson::GenericReader<rapidjson::UTF8, rapidjson::UTF8, rapidjson::CrtAllocator>::ParseObject<0u, rapidjson::EncodedInputStream<rapidjson::UTF8, rapidjson::MemoryStream>, rapidjson::GenericDocument<rapidjson::UTF8, rapidjson::MemoryPoolAllocatorrapidjson::CrtAllocator, rapidjson::CrtAllocator> >(rapidjson::EncodedInputStream<rapidjson::UTF8, rapidjson::MemoryStream>&, rapidjson::GenericDocument<rapidjson::UTF8, rapidjson::MemoryPoolAllocatorrapidjson::CrtAllocator, rapidjson::CrtAllocator>&)()
0x000000001077f158 VirtuosoServer!void rapidjson::GenericReader<rapidjson::UTF8, rapidjson::UTF8, rapidjson::CrtAllocator>::ParseObject<0u, rapidjson::EncodedInputStream<rapidjson::UTF8, rapidjson::MemoryStream>, rapidjson::GenericDocument<rapidjson::UTF8, rapidjson::MemoryPoolAllocatorrapidjson::CrtAllocator, rapidjson::CrtAllocator> >(rapidjson::EncodedInputStream<rapidjson::UTF8, rapidjson::MemoryStream>&, rapidjson::GenericDocument<rapidjson::UTF8, rapidjson::MemoryPoolAllocatorrapidjson::CrtAllocator, rapidjson::CrtAllocator>&)()
0x000000001077e8f0 VirtuosoServer!rapidjson::ParseResult rapidjson::GenericReader<rapidjson::UTF8, rapidjson::UTF8, rapidjson::CrtAllocator>::Parse<0u, rapidjson::EncodedInputStream<rapidjson::UTF8, rapidjson::MemoryStream>, rapidjson::GenericDocument<rapidjson::UTF8, rapidjson::MemoryPoolAllocatorrapidjson::CrtAllocator, rapidjson::CrtAllocator> >(rapidjson::EncodedInputStream<rapidjson::UTF8, rapidjson::MemoryStream>&, rapidjson::GenericDocument<rapidjson::UTF8, rapidjson::MemoryPoolAllocatorrapidjson::CrtAllocator, rapidjson::CrtAllocator>&)()
0x000000001077e7ac VirtuosoServer!rapidjson::GenericDocument<rapidjson::UTF8, rapidjson::MemoryPoolAllocatorrapidjson::CrtAllocator, rapidjson::CrtAllocator>& rapidjson::GenericDocument<rapidjson::UTF8, rapidjson::MemoryPoolAllocatorrapidjson::CrtAllocator, rapidjson::CrtAllocator>::ParseStream<0u, rapidjson::UTF8, rapidjson::EncodedInputStream<rapidjson::UTF8, rapidjson::MemoryStream> >(rapidjson::EncodedInputStream<rapidjson::UTF8, rapidjson::MemoryStream>&)()
0x00000000107cf996 VirtuosoServer!UnknownFunction()
0x0000000010893c53 VirtuosoServer!CesiumAsync::CesiumImpl::QueuedScheduler::dispatchInternal(bool)()
0x0000000010893b7a VirtuosoServer!CesiumAsync::CesiumImpl::QueuedScheduler::dispatchQueuedContinuations()()
0x00000000107ff26b VirtuosoServer!Cesium3DTilesSelection::Tileset::updateView(std::__1::vector<Cesium3DTilesSelection::ViewState, std::__1::allocatorCesium3DTilesSelection::ViewState > const&, float)()
0x000000000d8690cf VirtuosoServer!ACesium3DTileset::Tick(float) [V:/Virtuoso2023/Virtuoso/Plugins/CesiumForUnreal/Source/CesiumRuntime/Private/Cesium3DTileset.cpp:2032]
0x0000000009e15a3f VirtuosoServer!FActorTickFunction::ExecuteTick(float, ELevelTick, ENamedThreads::Type, TRefCountPtr const&) [U:/Source/UE5Git/UnrealEngine/Engine/Source/./Runtime/Engine/Private/Actor.cpp:238]
0x000000000b19e82a VirtuosoServer!FTickFunctionTask::DoTask(ENamedThreads::Type, TRefCountPtr const&) [U:/Source/UE5Git/UnrealEngine/Engine/Source/./Runtime/Engine/Private/TickTaskManager.cpp:275]
0x000000000b19e279 VirtuosoServer!TGraphTask::ExecuteTask(TArray<FBaseGraphTask*, TSizedDefaultAllocator<32> >&, ENamedThreads::Type, bool) [U:/Source/UE5Git/UnrealEngine/Engine/Source/Runtime/Core/Public/Async/TaskGraphInterfaces.h:1235]
0x0000000005281d66 VirtuosoServer!FNamedTaskThread::ProcessTasksNamedThread(int, bool) [U:/Source/UE5Git/UnrealEngine/Engine/Source/./Runtime/Core/Private/Async/TaskGraph.cpp:760]
0x00000000052806af VirtuosoServer!FNamedTaskThread::ProcessTasksUntilQuit(int) [U:/Source/UE5Git/UnrealEngine/Engine/Source/./Runtime/Core/Private/Async/TaskGraph.cpp:650]
0x000000000527f272 VirtuosoServer!FTaskGraphCompatibilityImplementation::WaitUntilTasksComplete(TArray<TRefCountPtr, TSizedInlineAllocator<4u, 32, TSizedDefaultAllocator<32> > > const&, ENamedThreads::Type) [U:/Source/UE5Git/UnrealEngine/Engine/Source/./Runtime/Core/Private/Async/TaskGraph.cpp:2122]
0x000000000b197708 VirtuosoServer!FTickTaskSequencer::ReleaseTickGroup(ETickingGroup, bool) [U:/Source/UE5Git/UnrealEngine/Engine/Source/./Runtime/Engine/Private/TickTaskManager.cpp:555]
0x000000000b1917ba VirtuosoServer!FTickTaskManager::RunTickGroup(ETickingGroup, bool) [U:/Source/UE5Git/UnrealEngine/Engine/Source/./Runtime/Engine/Private/TickTaskManager.cpp:1582]
0x000000000a7fddd2 VirtuosoServer!UWorld::Tick(ELevelTick, float) [U:/Source/UE5Git/UnrealEngine/Engine/Source/./Runtime/Engine/Private/LevelTick.cpp:1610]
0x000000000a5795fe VirtuosoServer!UGameEngine::Tick(float, bool) [U:/Source/UE5Git/UnrealEngine/Engine/Source/./Runtime/Engine/Private/GameEngine.cpp:1782]
0x000000000bc004fb VirtuosoServer!FEngineLoop::Tick() [U:/Source/UE5Git/UnrealEngine/Engine/Source/./Runtime/Launch/Private/LaunchEngineLoop.cpp:5915]
0x000000000bc06a3a VirtuosoServer!GuardedMain(char16_t const*) [U:/Source/UE5Git/UnrealEngine/Engine/Source/./Runtime/Launch/Private/Launch.cpp:182]
0x000000000bb6c04d VirtuosoServer!CommonUnixMain(int, char**, int ()(char16_t const), void (*)()) [U:/Source/UE5Git/UnrealEngine/Engine/Source/./Runtime/Unix/UnixCommonStartup/Private/UnixCommonStartup.cpp:269]
0x00007f6b9416f13a libc.so.6!__libc_start_main(+0xe9)
0x0000000005241029 VirtuosoServer!_start()

2

Hi @VirtuosoCEO,

I’m afraid the team hasn’t done much work with multiplayer, so I’m not sure how much we can help. But it would be useful overall to provide more info, such as:

  • Unreal Engine and Cesium for Unreal versions
  • What datasets you’re using in the level
  • A description of when the crash happens. Are there certain conditions or events that are more likely to cause the crash?

Thanks!

3

I am a using a source build of Unreal 5.4.4
Cesium GitHub Release version of 2.13.3
I am using Google Maps 3D Photorealistic Tiles.

It just crashes immediately on the load of the level, I assume when initially trying to load any data.
Linux servers don’t have a renderer and are just command line based, so it may have something to do with that

4

Hi @VirtuosoCEO,

Thanks for getting back to us. From your description, it sounds like you’re trying to render the data on the server itself, rather than client-side – is that correct? Or have I misunderstood?

It might help to talk through your multiplayer logic here. Depending on the scope of your game (e.g., if you’re hosting people around the entire globe), it might be unideal to have a single server instance of the 3D Tileset. But I acknowledge that doing client-side loading would greatly increase the number of root requests you’re making if you use Google Photorealistic 3D Tiles, which wouldn’t be great either…

5

Yes, this is the case.

In theory, the server doesn’t need to render it. I am using it as background geo/detail, however if its present at all, it causes a crash.

In the future, I’d like to use it as a gameplay element as well, so I know I will run into it then. If the geo/collision is recognized by the server regardless, the collision will cause mishaps.

I am using Photorealistic Tiles. I know costs may be intense, but for now, I try to get the basics to work and will worry about cost optimizations later