Unreal Engine Issues
Unreal Engine Issues
Static/stationary child actor components are invisible and/or move position when placed inside a dynamically loaded level
UE - Engine Scaling - Streaming - Oct 31, 2024When loading a non-world partitioned level into a persistent world partitioned level, parent actors with child actor components within the loaded map will move position or become invisible. Within t ...
Make literal container nodes (e.g. MakeArray) do not cast object ref output terms linked to interface-typed input pins.
UE - Framework - Blueprint - Jan 28, 2023As with most nodes, object reference outputs can be directly connected to interface-typed inputs on "make container" nodes (e.g. "MakeArray") if the object's class type implements the interface clas ...
Dangling pointer + mem corruption related to OwnerLastRenderTimePtr
UE - Engine Scaling - Streaming - Mar 16, 2026We've been seeing asserts and crashes related to OwnerLastRenderTimePtr. We've traced this to the mentioned pointer ending up dangling after using UActorComponent::Rename() on primitive components t ...
[CrashReport] UE4Editor_Engine!FPhysScene::SyncComponentsToBodies_AssumesLocked() [physscene.cpp:1271]
UE - Simulation - Physics - Dec 1, 2017This is a common crash in 4.18 and 4.18.1. The callstack shares similarities to [Link Removed], although that has been confirmed fixed in 4.18. Included in the same crashGroup are also a few Ensur ...
Distance field PrimitiveModifiedBounds grows unbounded when scene captures render with bDisableWorldRendering=true
UE - Rendering - Features - Oct 20, 2026When UGameViewportClient::bDisableWorldRendering is true and the scene is rendered only through manually triggered scene captures, FDistanceFieldSceneData::PrimitiveModifiedBounds is never reset and ...
Crash when enabling dynamic branch on static switches in Post Process Materials
UE - Rendering - Architecture - Materials - Jun 28, 2023[Link Removed] Some functions to access parameters don't take into account the newly added runtime static switch parameters. It should be straightforward to fix these up: void UMaterialInstance:: ...
[Mobile/Forward Rendering] PlanarReflection does not work when the reflection plane faces certain directions
UE - Platform - Mobile - Systems - Sep 24, 2025Note: This repros on 4.27 and all 5.x versions. When using the mobile renderer and/or forward shading, Planar Reflection will simply not work if the reflection plane normal has components that add ...
In 5.6, bWarningsAsErrors does not work with clang
UE - Core - Cpp Tools - UnrealBuildTool - Sep 20, 2025In 5.6, many warnings and errors specify their command line arguments to the compiler with these new C# attributes: [WarningsClangToolChain(["-Wno-date-time"], ["-Wdate-time", "-Wno-error=date-ti ...
[CrashReport] UE4Editor_MovieSceneTracks!UMovieSceneCameraCutSection::GenerateTemplate() [moviescenecameracutsection.cpp:24]
UE - Anim - Sequencer - Oct 30, 2017This is a somewhat common Sequencer crash that occurs in 4.17 and 4.18. User DescriptionsWas trying to copy and paste a camera movement but something screwed up, I tried to add an already built Cam ...
Instanced Actors: PCG on RuntimeGrid "None" assigns created IAManagers RuntimeGrid "MainGrid", causing cross-grid reference
UE - Graphics Tools - PCG - Graph - May 30, 2026Context PCG can be used to spawn Instanced Actors via the PCG IA Interop plugin, that makes Spawned Instanced Actors available as node. When a PCGActor placed in the level runs a PCG graph that spa ...