FStateTreeExecutionContext::GetDebugInfoString() outputs wrong info and crashes when using linked state trees

UE - AI - Debugging - Apr 17, 2025

When using State Trees, the AI Debugger can be accessed during play to show information about their current execution state. If a behavior tree is currently in a state that references a linked tree, ...

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, 2023

As 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 - World Creation - Worldbuilding Tools - Mar 16, 2026

We'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, 2017

This 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 ...

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:: ...

In 5.6, bWarningsAsErrors does not work with clang

UE - Core - Cpp Tools - UnrealBuildTool - Sep 20, 2025

In 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, 2017

This 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, 2026

Context 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 ...

MaterialTextureScale calculated incorrectly for materials with WorldPositionOffset

UE - Rendering - Architecture - Materials - Apr 16, 2024

When a Material uses WorldPositionOffset, the MaterialTextureScale is calculated incorrectly because FMaterialUtilities::ExportMaterialUVDensities() calls FMeshRenderer::RenderMaterialTexCoordScales ...

Using a FormatText node with Specifier in the same graph as an empty Macro will freeze the editor

UE - Gameplay - Blueprint - Jun 17, 2016

Using a FormatText node with Specifier in the same graph as an empty Macro will freeze the editor. Not using the Specifier or deleting the unused Marco will allow the BP to compile fine. **Only rep ...