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 ...

Instanced meshes do not accurately use volume light samples when lit in a statically lit scene

UE - Graphics Features - Aug 14, 2015

When using instanced meshes in a Blueprint or in foliage tool the indirect lighting cache will not correctly light these meshes. I've include a sample project with map to demonstrate what the lice ...

Viewport Flickers when opening a Blueprint and Setting it as a Docked Tab on El Capitan

UE - Platform - Apple - Apr 4, 2016

When docking a blueprint as a tab in the main viewport the sprites and other actors placed in the default scene (including player start) begin to flicker. This flicker persists until you close and ...

Large snap scaling causes meshes to scale 0

UE - Editor - Workflow Systems - Mar 3, 2016

With a large snap scale just selecting the uniform scaler will make the content scale to 0. It seems like it is far too easy for meshes to accidentally be scaled to 0 with snap scaling. Another exa ...

Indirect Lighting Cache causes Flickering on Skeletal Meshes

UE - Graphics Features - Apr 30, 2017

Indirect Lighting Cache is causing the Indirect Lighting for Skeletal Meshes to flicker. I have attempted both ILCQ Volume and Point cache qualities, and it seems Point produces the most exaggerate ...

[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 ...

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 ...

Crash on exit PIE after editing character blueprint of a code based side scrollers

UE - Gameplay - Apr 4, 2016

After editing character blueprint of a code based side scroller project, starting PIE will show the camera detached from the character and exiting PIE causes the project to crash. NOTE: This appear ...

Ensure starting PIE after editing character blueprint of a code based side scrollers

UE - Gameplay - Apr 6, 2016

After editing character blueprint of a code based side scroller project, starting PIE will show the camera detached from the character and exiting PIE causes the project to crash. NOTE: This appear ...