TickComponent and PostPhysicsTick in SkeletalMeshComponent can cause simultaneous read/write access

UE - Runtime - Animation - Jan 18, 2023

When a SkeletalMeshComponent is restarted by calling in order of   SetSimulatePhysics and SetComponentTickEnabled, the TickComponent and EndPhysicsTick are executed simultaneously. As a result, the ...

Blueprints from UE4 with dangling delegate reroute node crashes on UE5 load

UE - Framework - Blueprint Compiler - Dec 22, 2023

If a project from UE 4.27 or earlier has a blueprint with a reroute node dangling (no outgoing connection) from a Custom Event Node's delegate pin (red), this blueprint will crash when loaded in UE ...

Niagara Crash : ExportParticleDataToBlueprint module causes buffer overrun

UE - Rendering - Architecture - Niagara - Aug 10, 2021

This buffer overrun is probably caused by the ExportParticleDataToBlueprint module does not respecting the GPUAllocation Fixed Size setting in the module. In fact, out-of-range export data is not c ...

Crash on play if a BP uses a ClearInstances node followed by an AddInstance node

UE - Graphics Features - Jul 21, 2017

Crash on play if a BP manipulates a InstancedStaticMeshComponent by using a ClearInstances node followed by an AddInstance node. This is a blocker for the licensee. This is a regression: Working ...

Crash in FUniformExpressionSet::FillUniformBuffer trying access deleted UTextureCollection

UE - Rendering - Architecture - May 30, 2025

Crash in FUniformExpressionSet::FillUniformBuffer trying access deleted UTextureCollection (Experimental in 5.6). The licensee describes their crash, their analysis, and a proposed fix: This crash ...

Initializing custom Component on Actor in constructor causes odd hierarchy and details panel issues

UE - Gameplay - Blueprint - Feb 19, 2019

When testing with a simple setup, as follows: MySceneComponent has a UProperty(VisibleAnywhere, BlueprintReadOnly) of a USphereComponent pointer, initiated in the Constructor AMyActor has a UProper ...

Focus mode in the Editor does not handle Actors without PrimitiveComponent correctly, treating them as if they were at the origin (0,0,0), skewing the camera placement.

UE - Engine Scaling - Streaming - Nov 18, 2024

Focus mode in the Editor does not handle Actors without PrimitiveComponent correctly, treating them as if they were at the origin (0,0,0), skewing the camera placement. Some Actors like the WorldDat ...

Updating Material does not update platform stats in derived Instance

UE - Rendering - Architecture - Materials - Nov 26, 2024

It would seem that updating a material does not update the associated platform stats in a material instance editor, only the parameters. Can workaround by manually invoking shader compile in the ma ...

UMG widget callbacks do not set PIE context in editor

UE - Editor - UI Systems - May 21, 2018

This is from a UDN post. Several gameplay functions, such as level streaming and SoftObjectPtr resolution, depend on the GPlayInEditorID being set when that code is executed in PIE in the editor. T ...

The light in the Blueprint Editor's Preview Scene does not respond to any lighting channel but 0.

UE - Framework - Blueprint Editor - Jun 28, 2024

In the Blueprint Editor, Primitive Components can be configured to respond to Lighting Channels 0, 1, and/or 2. However, if channel 0 is disabled (even with another one enabled), the Preview Actor's ...