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 ...

D3D12RHI keeps increasing uniform buffer memory with "stat RHI"

UE - Rendering Architecture - RHI - Oct 25, 2019

If any skeletal meshes are not displayed, it stops increasing. Allocation count of uniform buffer is stable. added on February 26 Followings are an additional information from licensee. FD3D12 ...

Ribbons Don't Follow Their Source Particles When Scaling

UE - Niagara - Mar 23, 2020

When Ribbon Data in a particles system that is following is scaled in an instance the ribbons scale appropriately, but they don't follow updated location of their source particles. See the attached ...

Launching Android project to device results in Assertion Failed: AsyncLoading.cpp, Line 3710

UE - Platform - Mobile - Aug 31, 2020

After updating to 4.25.1 from 4.25 Packaged Android game crashes constantly with objects added to the map 4.25 Packaged game did not crash (editor did a lot but glad thats fixed in 4.25.1) Empty map ...

Replacing a UI widget element and then undoing it causes the Widget Blueprint's UI elements to be deleted on editor restart

UE - Editor - UI Systems - Jan 25, 2021

When using the Replace With option and then undoing it, upon engine restart the Widget Blueprint's UI components are all removed from the Widget Blueprint. It seems the undo is crucial to the issue, ...

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 - Graphics 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. ...

BSOD when launching Twinmotion on NVIDIA 50-series GPUs with 576.02 Drivers

TM - Rendering - Apr 22, 2025

Reported from multiple users. NVIDIA RTX 50-series GPU users are reporting BSODs when attempting to launch Twinmotion with the latest drivers installed. The crashes occur on the 576.02 driver versi ...

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

UE - Editor - 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 ...

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 ...