Crash in Unreal 5.5

I had no issues prior to last week but suddenly whenever Cesium load in my level, it keeps crashing.

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Unhandled Exception: EXCEPTION_ACCESS_VIOLATION writing address 0x0000000000000000

UnrealEditor_CesiumRuntime!bl::RasterEngine::solidOverrideFillU8()
UnrealEditor_CesiumRuntime!bl::RasterEngine::fillAll<0>() [D:.ezvcpkg\dbe35ceb30c688bf72e952ab23778e009a578f18\buildtrees\blend2d\src\fc85f14251-f50748665f.clean\src\blend2d\raster\rastercontext.cpp:2724]
UnrealEditor_CesiumRuntime!CesiumVectorData::VectorRasterizer::VectorRasterizer()
UnrealEditor_CesiumRuntime!CesiumRasterOverlays::RasterizedPolygonsTileProvider::loadTileImage()
UnrealEditor_CesiumRuntime!async::detail::task_func<CesiumAsync::CesiumImpl::ImmediateSchedulerCesiumAsync::CesiumImpl::TaskScheduler,async::detail::root_exec_func<CesiumAsync::CesiumImpl::ImmediateSchedulerCesiumAsync::CesiumImpl::TaskScheduler,CesiumRa()
UnrealEditor_CesiumRuntime!CesiumAsync::CesiumImpl::ImmediateSchedulerCesiumAsync::CesiumImpl::TaskScheduler::SchedulerScope::~SchedulerScope()
UnrealEditor_CesiumRuntime!UnrealTaskProcessor::startTask'::2’::<lambda_1>::operator()() [D:\build\U5M\Sync\LocalBuilds\PluginTemp\HostProject\Plugins\CesiumForUnreal\Source\CesiumRuntime\Private\UnrealTaskProcessor.cpp:10]
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Hi @VizSim, welcome to the community!

Sorry you’re running into a crash. Can you provide any more information that might help us reproduce (or at least understand) this problem? Did it start when you upgraded to a new version of Cesium for Unreal? Or when you added something specific to your level? Ideally, if you can give us specific instructions for getting to this crash, preferably starting with the Cesium for Unreal Samples project, we can investigate and fix it.

hi Kevin, I am running into the exact same error, here is my crash report:

I am using Version 2.19.1

I have a cartographic polygon for the exterior of my scene using the Material Layer Key (ClippingExterior) which excludes everything outside of that polygon region. It’s a basic square shape

I also have an interior clipping using a Material Layer Key (Clipping) which is a cartographic polygon with many points forming a custom zone that I want as a cutout from the Google Photorealistic 3D Tiles. I believe this is the one that is causing issues with my crashing. If I use a default Cesium Cartographic Polygon it doesn’t crash. But maybe the complexity of my custom Cartographic Polygon is causing issues? Like the previous user, I never had this issue before until recently.

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Unhandled Exception: EXCEPTION_ACCESS_VIOLATION writing address 0x0000000000000000

UnrealEditor_CesiumRuntime!bl::RasterEngine::solidOverrideFillU8()
UnrealEditor_CesiumRuntime!bl::RasterEngine::fillAll<0>() [D:.ezvcpkg\dbe35ceb30c688bf72e952ab23778e009a578f18\buildtrees\blend2d\src\fc85f14251-f50748665f.clean\src\blend2d\raster\rastercontext.cpp:2724]
UnrealEditor_CesiumRuntime!CesiumVectorData::VectorRasterizer::VectorRasterizer()
UnrealEditor_CesiumRuntime!CesiumRasterOverlays::RasterizedPolygonsTileProvider::loadTileImage()
UnrealEditor_CesiumRuntime!async::detail::task_func<CesiumAsync::CesiumImpl::ImmediateSchedulerCesiumAsync::CesiumImpl::TaskScheduler,async::detail::root_exec_func<CesiumAsync::CesiumImpl::ImmediateSchedulerCesiumAsync::CesiumImpl::TaskScheduler,CesiumRa()
UnrealEditor_CesiumRuntime!CesiumAsync::CesiumImpl::ImmediateSchedulerCesiumAsync::CesiumImpl::TaskScheduler::SchedulerScope::~SchedulerScope()
UnrealEditor_CesiumRuntime!UnrealTaskProcessor::startTask'::2’::<lambda_1>::operator()() [D:\build\U5M\Sync\LocalBuilds\PluginTemp\HostProject\Plugins\CesiumForUnreal\Source\CesiumRuntime\Private\UnrealTaskProcessor.cpp:10]
UnrealEditor_Core
UnrealEditor_Core
UnrealEditor_Core
UnrealEditor_Core
UnrealEditor_Core
UnrealEditor_Core
UnrealEditor_Core
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Hi @Art_C, thanks for the details!

We’re still trying to figure out what is causing this. In the meantime, the best option is probably to downgrade your Cesium for Unreal version (v2.17.0 should not have the issue).

At this point, it looks like it might be a bug in blend2d, which is a third-party library we switched to for cartographic polygon rasterization in v2.18.0. But it could also be something subtle that we’re doing wrong in the plugin that is triggering the crash inside the third-party code.

If we don’t find a better solution before then, we’ll revert to the old rasterization approach in the early October release.

thanks Kevin for the suggestion, I rolled back to 2.17.0 last week as that was the latest stable version that worked. Will stay tuned for an update!

Cheers,

Arthur