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 ...

ApplyLocalExposure uses Output_ExtentInverse instead of Output_ViewportSizeInverse for bilateral grid UV

UE - Rendering - Graphics Features - May 18, 2026

The ApplyLocalExposureCS shader in PostProcessLocalExposure.usf computes UV coordinates for the LumBilateralGrid 3D texture using Output_ExtentInverse (1/RenderTargetSize) instead of Output_Viewport ...

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. ...

[CrashReport] UE4Editor_UnrealEd!SCurveEditor::OnObjectPropertyChanged

Tools - Aug 1, 2017

This is a common crash that has affected more than 170 users since at least 4.15 and occurring into 4.17. Based on one user description and frequent project names, this appears to commonly correla ...

[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 ...

CheckCompilingPSOs assert in FMaterialPSORequestManager::MarkCompilationComplete fires occasionally

UE - Rendering - Architecture - RHI - May 17, 2025

Find the root cause and fix it. Potential issue based on logs:New RequestA is created in PrecachePSOs and its collection task is dispatched and finishedRequestA is waiting for compilation taskReque ...

LevelStreamingPersistence: BP variables that aren't Instance Editable get reset

UE - World Creation - Worldbuilding Tools - Mar 6, 2026

Context The LevelStreamingPersistence plugin can be used to remember and restore properties on actors and components that are part of a streamed level. Blueprint variables can be marked as instan ...

[CrashReport] UE4Editor_UnrealEd!TSet<FEditorUndoClient * | SActorDetails::~SActorDetails

Tools - Sep 20, 2017

This is a somewhat common crash coming out of 4.16 and 4.17. Users have not provided any description of their actions when the crash occurred. The top line of the callstack and the source context ...

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 ...