Unreal Engine Issues
Unreal Engine Issues
Chaos : Rigid body sleeps when very small external force is applied by AddForce
UE - Simulation - Physics - Solver - May 25, 2022When 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, 2024This 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, 2025From 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, 2025There'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, 2017This 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, 2018User 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
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 ...
[CrashReport] UE4Editor_UnrealEd!TSet<FEditorUndoClient * | SActorDetails::~SActorDetails
Tools - Sep 20, 2017This 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, 2021This 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, 2023User reports: I've noticed a bug with PlayMontageAndWait There are 4 possible triggers when a Montage completes:OnCompletedOnBlendOutOnInterruptedOnCancelled Once OnBlendout has been triggere ...