Can change type of event dispatcher in Blueprint

UE - Gameplay - Blueprint Editor - Oct 2, 2018

It seems that with 4.20 users are able to change a dispatcher's type from Multicast Delegate to something else (float, int, etc.) Doing so will cause any node that references the dispatcher via call ...

GAS: Ability that destroys owning actor on activate causes crashes due to ABILITYLIST_SCOPE_LOCK

UE - Gameplay - Gameplay Ability System - Oct 31, 2023

A GameplayAbility that destroys its owning actor inside ActivateAbility() causes a crash, because actor destruction will modify the ability list but ActivateAbility() is called within an ABILITYLIST ...

UMG/Slate scroll bars have a minimum size for scaling

UE - Editor - UI Systems - Mar 14, 2017

A user has reported an issue about scroll bars having a minimum size in UMG and Slate code, causing them to not scale correctly when the scroll box is at a smaller size. This affects both horizontal ...

[CrashReport] UE4Editor_CoreUObject!TFastReferenceCollector<1,FGCReferenceProcessor<1>,FGCCollector<1>,FGCArrayPool,0>::ProcessObjectArray()

UE - Foundation - Core - UObject - Jul 19, 2017

This is a common crash affecting users in 4.16. Over 100 users have been affected, although they have not provided additional information. Source Context 469 TokenStreamIndex++; 47 ...

Sequencer animations using Skeletal Mesh Pose don't play properly if following another sequence with an animation using Keep State

UE - Anim - Sequencer - Feb 20, 2019

The bug affects skeletal mesh animations when played in sequencer with AnimBP after another animation which was set to Keep State. This is a follow-up to [Link Removed]. Two animations now play cor ...

Cannot Parse a Custom Node as a Function Input to Another Custom Node In The Material Editor

UE - Graphics Features - Aug 30, 2018

Cannot parse a Custom node as a function input to another Custom node in material editor. This is working as expected in 4.18 CL# 3832480. Found in 4.19 CL# 4033788, 4.20 CL# 4302132, and 4.21 CL# ...

Callling "Get[AxisMapping]" or adding AxisMapping Event node in blueprint will break code input implementation for that axis mapping

UE - Gameplay - Input - Aug 17, 2016

When character input is defined in code, adding a call to the Get[AxisMapping] node in blueprints causes input for the specific mapping to fail. Note: This only affects code based input, Blueprint ...

BSP brushes get Clipped or Disappear relative to the Surface Normals of a nearby Brush when Deleting/Flipping Faces

UE - LD & Modeling - Modeling Tools - BSP - May 1, 2017

While testing this issue it was interesting to discover how the surrounding BSP's were affected. They seemed to clip/disappear according to the surface normals of the deleted brushes. There is a si ...

Missing Triangles on scaled MetaHuman assets with Nanite enabled

UE - Rendering - Graphics Features - Nanite - Feb 19, 2025

Additional information: only happens when all three conditions are true: the camera is very close to the character, the MH is Nanite, and a scaled mocap animation is appliedmaterial is opaque, shows ...

Camera Actor variable (array) no longer editable in Blueprints

UE - Gameplay - Jun 7, 2018

This is a regression from 4.19. In 4.19 you were able to change the actor assigned to the array element in a Camera Actor variable. In 4.20 and 4.21 the field is grayed out and displays None with a ...