Bug - Animations and Keep State Fail when scrubbing backward.

UE - Anim - Sequencer - Jan 30, 2020

If you scrub past an animation with keep state, and scrub into an animation with defaults everything is fine. When you scrub back to the animation with keep state, the animation breaks, until there ...

Color space transform in the UI composition is incorrect on DX12 HDR (r.HDR.UI.CompositeMode=1)

UE - Graphics Features - Jun 11, 2021

Color space conversion in the UI composition is incorrect on DX12 HDR. In the main() function In CompositeUIPixelShader.usf, you can see the following color space transform.// sRGB -> RRT -> ODT ...

Material slot assignment incorrect after mesh reduction completely removes all triangles from a section

UE - Editor - Content Pipeline - Asset Build - Apr 28, 2022

When mesh reduction results in a section becoming empty, the material slots are incorrectly assigned. e.g. if section 0 gets removed due to it having no triangles after reduction, then its material ...

Deferring Blueprint CDO construction at load time is leading to some data loss.

UE - Gameplay - Blueprint - Jan 27, 2023

Various licensees are reporting data loss on load due to the change that was made for [Link Removed] in which we now defer Blueprint CDO construction on load until the finalization phase. This issu ...

[CrashReport][Assert] UnrealEditor-RHI!FRHIResource::MarkForDelete() [Engine/Source/Runtime/RHI/Private/RHIResources.cpp:49]

UE - Rendering Architecture - Materials - Dec 18, 2024

One of the users described this issue as below. "At seemingly random times while working in the material graph, some action will cause a hitch or freeze, and quickly after the engine will crash, an ...

EditCondition specific does not prevent values from being changed.

Tools - Mar 9, 2017

1) Using the Meta specifier EditCondition will gray out the property box so that it cannot be clicked, but using tab from another property box will place the cursor inside the grayed out box. 2) V ...

UKismetArrayLibrary::GenericArray_Shuffle is weighted to return some results more than others

UE - Gameplay - Aug 15, 2017

The implementation of UKismetArrayLibrary::GenericArray_Shuffle() will generate certain array shuffle results more often (up to three times as much) than others, rather than having a roughly equal c ...

Skeletal Meshes have physics collisions lag

UE - Simulation - Physics - Oct 2, 2019

Skeletal mesh's physics collision lag behind the actual mesh. It didn't matter if there was just a root bone or multiple bones/constraints. This doesn't happen when using static meshes. The effect ...

Changing the name of a native component results in a blank details panel

UE - Gameplay - Components - May 7, 2021

Much like [Link Removed] (which I'm backing down on my by design claim), there is an issue where if you previously referenced a component that no longer exists, the correct instanced subobject is lo ...

Subsurface Scattering Checkerboard with SceneColourFormat 3 (High Scalability) leads to a visual artefact when temporal upscaling is in use

UE - Graphics Features - Sep 30, 2024

Primarily visible at very low internal resolutions (25-33%), the SSS checkerboard with an RGB scene colour format (r.SceneColorFormat 3) causes a double-image artefact both internally and on the sil ...