Crash caused by Buffer Overread in TBitArray operator < function

UE - Foundation - Core - Aug 29, 2018

A licensee has reported a crash that is caused by a Buffer Overread in TBitArray's operator < function. While the licensee did not provide reproduction steps, the crash is apparent from looking at t ...

Crash on loading pre-4.20 cloth data when compute skin cache is enabled in 4.21

UE - Graphics Features - Mar 19, 2019

According to information from the licensee, the else clause was added to "FSkeletalMeshLODModel::(GetClothMappingData()" at CL 4437969 , but if it is the cloth data existing from 4.20 or earlier, it ...

Compile on load crashes for classes within an abstract class

UE - Gameplay - Blueprint Compiler - Feb 20, 2021

When compiling on load in -game, a blueprint class that inherits from a native class that is marked within and the class that it is within is abstract, a crash will occur when FBlueprintCompilationM ...

Incorrect volume bounds check in FTranslucentLightInjectionCollector::AddLightForInjection

UE - Rendering - Features - Apr 8, 2025

The 'VolumeBounds' array in FTranslucentLightInjectionCollector::AddLightForInjection is accessed as a pointer instead of with 'VolumeCascadeIndex' and thus fails bounds checks for the outer volume. ...

Setting Slate.ShowBatching to 1 makes the entire screen green unexpectedly

UE - AI Workflows - UI Systems - Slate - Jun 19, 2025

This issue may have occurred due to a refactoring of the related functionality during the engine update from version 5.4 to 5.5. The main reason is that the randomization of BatchColor doesn't work ...

Rear tires on vehicle in VehicleGame sample detach and drift back from axel as user accelerates

OLD - Anim - May 3, 2017

This is a regression from 4.15 as it is unreproducible on a binary build in //UE4/Release-4.15 @ 3416026. Both my 4.15. and 4.16 versions were obtained from the EGL. The more the higher the speed t ...

[CrashReport] UE4Editor_MaterialEditor!FMaterialEditor::OnCanPromoteToParameter()

UE - Rendering - Architecture - Materials - Jun 27, 2017

This is a common crash in the 4.16 release. It seems related to creating a parameter in the Material Editor, however users have not provided any descriptions so additional information is not current ...

SunTemple scene does not update properly on iPhone 6S

UE - Platform - Mobile - Jul 18, 2017

On the 6S, the SunTemple scene is almost unresponsive. As the player uses the thumbsticks, the lightmaps from the windows rotate to mach the player's movement; but they are the only thing. This doe ...

Copy/pasting component results in broken duplicate component (named _GEN_VARIABLE)

UE - Gameplay - Components - Jul 28, 2017

REGRESSION: Yes. Does not occur in 4.16.3 Using Copy/Paste to duplicate a component will result in a broken duplicate component. This doesn't occur if the user uses Ctrl+W to duplicate. On compi ...

Certain combined Linear/Angular movements cause Client to freeze for several seconds

UE - Simulation - Physics - May 24, 2019

When using Replicated Movement, certain combined linear/angular movements cause the client to freeze for several seconds and then catch up to the server. This is a regression from 4.21.2 (CL-4753647 ...