BlackboardComponent observer can be called for the wrong key

UE - AI - BehaviorTree - Feb 7, 2023

We need to, at least, prevent this by clearing observers when running a new BT using a different blackboard. Must also think that this might affect licensees relying on the current behavior (might h ...

GameplayAbilitiesSystem: GameplayCues OnRemoved never firing

UE - Gameplay - Gameplay Ability System - Nov 15, 2023

This behaviour was introduced in the following changelists in 5.3: CLs 25371706 and 25407985 https://github.com/EpicGames/UnrealEngine/commit/6e985ceeb98bc0d166756ccd3e3c0b0350d02265https://github. ...

TranslucentVolumeAmbient is darkened in InjectTranslucencyLightingVolume pass when using VSMs with r.Shadow.Virtual.ForceOnlyVirtualShadowMaps is Off

UE - Graphics Features - Shadows - Nov 18, 2024

CSM targets are still created and affect the InjectTranslucencyLightingVolume pass when moving in a project that only uses VSM causing over brightening of fog planes and other translucent meshes. r ...

Popping Ribbon UVs

UE - Niagara - Mar 10, 2025

Please see the Additional Link for related UDN information. The UV popping described can be subtle, depending on settings; it's affected by spawn rate and GPU vs CPU. The popping shown in the gif t ...

Adding SmartObjectZoneAnnotationComponent to a blueprint actor causes a crash when building the package

UE - AI - SmartObject - Jan 30, 2025

If placing an actor with SmartObjectZoneAnnotationComponent added to blueprint actor in a level, it will crash when the level open. As a workaround, adding SmartObjectZoneAnnotationComponent to the ...

Editor primitives render incorrectly in stereoscopic with instanced stereo

UE - Platform - XR - Aug 17, 2016

Trigger box icons move around when oculus head movement is used. Found in //UE4/Release-Staging-4.13 @ 3090357 QA-Promotion map Edit: 08-22: This affects volumes as well as their editor icons, upd ...

Projects using a class that inherits from SceneCapture2D may crash on launch on iOS devices

UE - Platform - Mobile - Jan 4, 2016

If a project uses a class that inherits from SceneCapture2D and sets the render target via code, the project will crash on launch on an iOS device. The project runs normally on PC and Android. Proj ...

Changes to Landscape Thickness not propegated to PhysX

UE - LD & Modeling - Terrain - Landscape - Jun 3, 2015

In 4.8 preview 4, it appears that changes made to a landscape actor's CollisionThickness property in the editor are not being replicated in physX [...] It appears that what happens is that the engin ...

Using FEditorModeID for the "Mode" console command does not switch the modes tab

Tools - May 10, 2016

Using the FEditorModeID for the different editor modes does not affect actual modes available in editor Modes tab. Example: Command "Mode EM_Foliage" does not switch to the foliage mode Workaround ...

Cursor breaks viewport when using Widget Render Transform Scale

UE - Editor - UI Systems - Mar 14, 2017

The viewport cursor will continue to display off of the actual viewport until the widget ends if the border component actually extends. This has not been tested with any other template. Regression ...