[CrashReport] UE4Editor_UnrealEd!TArray<TSharedRef<FAssetThumbnailPool::FThumbnailInfo,0>,FDefaultAllocator>::AddUniqueImpl<TSharedRef<FAssetThumbnailPool::FThumbnailInfo,0> const & __ptr64>() [array.h:1805]

Tools - Sep 20, 2017

This is a longstanding crash that occurs with low frequency per release, but has affected 400 users since the 4.11 release. Unfortunately among all of them, only one has provided any description. ...

ProxyLOD plugin generates uninitialized vertices at end of a vertex buffer

UE - World Creation - Worldbuilding Tools - HLOD - Sep 11, 2020

ProxyLOD::FQuadricMeshSimplifier::OutputMesh may remove duped verts. The input vertex buffer was resized by numVerts from FQuadricMeshSimplifier before calling OutputMesh. So these behaviors genera ...

UMG: Drag-drop widgets get stuck at (0, 0)

UE - Editor - UI Systems - UMG - Nov 7, 2022

Reported on the dev forum, drag-drop widget is broken in the 5.1 Preview.https://forums.unrealengine.com/t/unreal-engine-5-1-preview/662523/221 Anyone else having problems with UUserWidget::SetPosi ...

Missing PSO Precaches in the engine

UE - Rendering Architecture - RHI - Aug 20, 2025

A licensee wanted to report some missing PSO Precaching they found, which they have fixed locally: 1. UCableComponent doesn't implement CollectPSOPrecacheData or call CheckPSOPrecachingAndBoostPri ...

FPS Perf Regression on 980

UE - Graphics Features - Mar 17, 2015

At least one user has so far reported a noticeable drop in FPS from 4.6.1 to 4.7.2 in a heavy scene; using a GTX 980. I've reproduced a perf drop in a cooked 4.7 build of elemental demo compared to ...

UK2Node_EnumLiteral always outputs defaulted (0) value if input pin is connected

UE - Gameplay - Blueprint - Sep 28, 2018

The reported behavior repros in 4.20 and 4.21, but does not repro in 4.19. Regarding the "Literal Enum" node in blueprints: When an input enum value is connected to the input pin, the output is al ...

[CrashReport] GPUCrash - exiting due to D3D device being lost - D3D Hung - Nvidia

UE - Graphics Features - May 14, 2019

Separating [Link Removed] into Nvidia and AMD tickets.This ticket will house Nvidia information Exported data on 5/14/2019 with following Query:1 Month Time FrameMajorVersion is 4.22.1Callstack Con ...

Lighting channels not working as expected when enabling Ray Tracing Shadow

UE - Graphics Features - Lumen - Oct 13, 2020

Non-Ray Tracing Shadows are only cast from lights on meshes assigned to the same Lighting Channel. When enabling Ray Tracing Shadows this is not the case. Lights will still cast Ray Tracing Shadows ...

Variant manager crash in UPropertyValue::HasValidResolve

UE - Editor - Content Pipeline - Variants - Nov 21, 2024

in the past we have reported a lot of VM related bugs which got fixed over time. Unfortunately, I think we have another one. Right now we're using 5.0.3 binaries from the launcher. Now the pro ...

Multiple setter functions in UMaterialEditingLibrary always return false even when the parameter is correctly set on the MaterialInstance.

UE - Rendering Architecture - Materials - May 30, 2025

In Unreal Engine, materials can expose parameters that can then be modified via instances (MaterialInstanceConstant). The UMaterialEditingLibrary provides several functions to modify these parameter ...