Unreal Engine Issues
Unreal Engine Issues
Editor crashes in FAsyncLoadingThread2::ProcessLoadedPackagesFromGame when Level Blueprint references external actor
UE - Engine Scaling - Streaming - Level Instances - Jun 26, 2026Adding a reference to an external actor in the level blueprint causes the package for the actor to be put in the import table of the level. In some cases, the actor package can end up calling postlo ...
Custom expression additional outputs don't work when connected to World Position Offset
UE - Rendering - Architecture - Materials - Jun 24, 2026Custom expression additional outputs are considered (0,0,0) when connected to WPO. ...
Apply mesh paint Blueprint instance changes and save fails
UE - Rendering - Architecture - Materials - Jun 22, 2026After mesh painting on a BP Static Mesh Actor, and "Apply instance changes to Blueprint" the added virtual texture is removed with the log:LogTexture: Display: Building texture TwoD: /Game/FirstPers ...
Crash when applying Decal material with Distance Cull Fade node to Decal Actor
UE - Rendering - Architecture - Materials - Jun 15, 2026The Editor crashes when applying a Material with a Distance Cull Fade node to a Decal Actor. Fatal error: [Link Removed] [Line: 730] Missing uniform buffer at slot 2, stage SF_Pixel. Please check ...
Nanite Landscape Visibility Layer Crash
UE - Graphics Tools - Terrain - Landscape - Jun 10, 2026Upon saving the level after creating the landscape and painting visibility, the editor crashes. When you restart the editor and load the level, you are greeted with a warning in the upper right corn ...
[USD EXPORT] USD Exporter does not export subsequence data from the master sequence
UE - Editor - Open File Formats - Jun 9, 2026As described in the steps to reproduce, when exporting a selected binding somwehere in a sequence hierarchy into usd, the export yields an empty result when using 'selection only' option. The export ...
Assert crash when playing Groom Cache with Card Mesh LOD
UE - Rendering - Graphics Features - May 29, 2026Playing a Guides Groom Cache while Card Mesh LOD (Guide-Based) is active causes an assert in RunHairStrandsInterpolation_Cards when the renderer switches to Card LOD. Assert location:Plugins/Runtim ...
Niagara Mesh Renderer registers NumParticles x NumMeshVariants TLAS instances
UE - Rendering - Graphics Features - Ray Tracing - May 28, 2026When using the Niagara Mesh Renderer with multiple mesh variants selected via MeshIndex, the number of TLAS instances allocated is NumParticles × NumMeshVariants and enabling the Path Tracer can ca ...
check(bRenderStateCreated) fires in SendRenderDynamicData_Concurrent called from FRegisterComponentContext::Process
UE - Rendering - Architecture - RHI - May 18, 2026FRegisterComponentContext::Process() in ActorComponent.cpp iterates over SendRenderDynamicDataPrimitives and calls SendRenderDynamicData_Concurrent() on each. The existing guard checks ::IsValid(Pri ...
Meshes with scaled root bones pop when entering simulation
UE - Runtime - Simulation - May 15, 2026This issue is fallout from the changes in 33851494. Prior to that, we didn’t get the pop on beginning the sim. The problem appears to be that in USkeletalMeshComponent::PerformBlendPhysicsBones we ...