Chaos : Rigid body sleeps when very small external force is applied by AddForce

UE - Simulation - Physics - Solver - May 25, 2022

When a small external force is applied to the rigid body, the VSmooth value is reset in the ResetVSmoothFromForces function. Since this function ignores the current velocity, a very small velocity ...

Widgets will bind input delegates to the Player Controller's Input Component, but never unbind them

UE - Editor - UI Systems - UMG - Jan 30, 2024

This is a bug introduced with 18468289 a while ago. We added this functionality for [Link Removed], which allows input event nodes to be placed within widgets and have them behave correctly.  This ...

Typo in GetAsBoundsArray() from file AABBTree.h on Chaos module

UE - Simulation - Core - Jul 30, 2025

From file [Engine\Source\Runtime\Experimental\Chaos\Public\Chaos\AABBTree.h], function Chaos::TAABBTree<>::GetAsBoundsArray(): bool GetAsBoundsArray(TArray<TAABB<T, 3>>& AllBounds, int32 NodeIdx, i ...

Setting a struct bool property (bitfield) to itself writes the wrong value

UE - Framework - Blueprint Compiler - Sep 17, 2025

There's an issue when assigning a bitfield bool to a native bool in Blueprints. Currently, the engine erroneously treats the memory for a local bool as a uint8 bitfield, which is undefined behavior. ...

A camera set to Orthographic projection mode with a negative Ortho Width will crash the editor on PIE

UE - Graphics Features - Jan 22, 2015

A camera set to Orthographic projection mode with a negative Ortho Width will crash the editor on PIE. Reproduced in Main (CL-2412886) Crash Report: [Link Removed] Call Stack:<unknown module>! UE ...

[CrashReport] UE4Editor_Engine!FPointerToUberGraphFrame::~FPointerToUberGraphFrame()

UE - Gameplay - Blueprint - Aug 15, 2017

This is a trending crash coming out of the 4.17.0 release. Users have not provided any descriptions of their actions when the crash occurred, however the callstack is very similar to [Link Removed] ...

[CrashReport] UE4Editor_Landscape!FLandscapeComponentSceneProxy::FLandscapeComponentSceneProxy() [landscaperender.cpp:680]

UE - LD & Modeling - Terrain - Landscape - Apr 11, 2018

User comment in crash group:Wanted to delete a single field of my landscape wich is very big. Same error appears if I try to get a part of the landscape to another streaming level. Would be cool if ...

Undo/Redo can cause the gizmo to desync from a leaf-selected component

UE - Editor - Workflow Systems - Oct 18, 2021

This is a regression from 4.27. This is happening because of the change to typed elements. UEditorEngine::PostUndo, when combined with the typed element changes causes the selection set to reorder ...

AbilityTask_PlayMontage will 'zombie' if Interrupted during BlendOut

UE - Gameplay - Gameplay Ability System - Apr 14, 2023

User reports: I've noticed a bug with PlayMontageAndWait There are 4 possible triggers when a Montage completes:OnCompletedOnBlendOutOnInterruptedOnCancelled Once OnBlendout has been triggere ...

Niagara module inputs don't handle bitfield enums correctly

UE - Niagara - Feb 17, 2025

As one clicks on the enum fields trying to form an input, the log is written with a variation of the following: [2025.02.14-17.42.38:940][521]LogNiagaraEditor: Error: Error getting default value fo ...