Movie Scene Capture - DX12 Render Artifacts and Delay

UE - Rendering - Architecture - RHI - Jun 19, 2023

If using the Legacy renderer (Movie Scene Capture) with DefaultRHI DirectX12, there's new delay and also some frames get weird artifacts.   However, the delay and artifacts do not appear when using ...

Soft angular constraints solve velocity like hard constraints

UE - Runtime - Simulation - Jul 17, 2025

Soft angular constraints are solving velocity like hard constraints. Instead of swinging back and forth, the affected body just snaps to 45 degrees. Check the steps to reproduce for more details. Th ...

HISM causing massive spikes in BuildTreeAsync

UE - Rendering - Architecture - Feb 12, 2026

Loading a world partition cell containing dense foliage (30k+ instances per cell) causes spikes on lower end hardware of up to 10-15ms and can observe spikes of 2-5ms on high end hardware too primar ...

Setting NavModifierVolume's AreaClass at runtime does not result in navmesh rebuilding

UE - AI - Apr 23, 2015

The volume does accept the change and if it gets moved the navmesh will rebuild with new area set. The core issue is that setting NavModifierVolume.AreaClass at runtime does not notify navigation sy ...

Crash while closing Create Blank New Blueprint window after attempting to name blueprint the same name as another blueprint

UE - Gameplay - Blueprint - Jul 27, 2016

Crash while closing Create Blank New Blueprint window after attempting to name blueprint the same name as another blueprint. This crash only occurs when attempting to close the window using the "X" ...

[CrashReport] UObjectBaseUtility::GetOutermost | FArchiveInvalidateTransientRefs::operator<<

UE - Gameplay - Blueprint - Sep 7, 2017

This is a somewhat common crash affecting users in 4.17. They have not provided any descriptions of their actions when the crash occurred. Source Context 110 /** 111 * Walks up ...

Hot reload can prevent code components from being accessible in blueprints

UE - Foundation - Cpp Tools - Hot Reload - Sep 29, 2017

When a class is edited / hot reload preformed, code based components are sometimes removed from the MyBlueprint > Variables section and cannot be dragged from the Components tab into the graph with ...

Flickering in Material Editor Preview when Absolute World Position node used

UE - Graphics Features - Oct 17, 2017

Creating a material with "Absolute World Position" node plugged into the "World Position Offset" input of the base Material node results in flickering in the preview window of the material editor. ...

Static mesh's material slot's cast shadow does not require a build of StaticLight

UE - Graphics Features - Dec 7, 2017

If static mesh's material slot's cast shadow is changed, UE4 does not show "LIGHTING NEEDS TO BE REBUILT". I solved it with the following fixes. StaticMeshEditorTools.cpp void FMeshSectionSettin ...

Cannot run any packaged project if "Force all skinned meshes to recompute tangents" has been enabled in an unrelated project

UE - Foundation - Core - Apr 20, 2018

Enabling the "Force all skinned meshes to recompute tangents" sets the value at a Windows user level so that it affects all UE4 projects opened by that user, including unrelated packaged projects. T ...