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 ...

CLion cannot update CMake for an Unreal Studio project created on a drive other than the one the Engine is installed on

UE - Foundation - Cpp Tools - Apr 22, 2019

If an Unreal Studio project is created on a different drive from where the Engine is installed, CLion is unable to successfully update CMake. The location for where Engine files can be found appears ...

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 ...

Creating a new C++ Synth Component results in a failed compile linker error.

UE - Audio - Dec 19, 2019

Upon creating a new Synth Component C++ Class in Unreal 4.24, the compiler will fail to compile with a Linker error. ...

Empty Shot Track Breaks Camera Component tracks when using Camera Cut Track

UE - Anim - Sequencer - Aug 18, 2016

Empty Shot Track Breaks Camera Component tracks when using Camera Cut Track ...

[CrashReport] UEdGraphPin::Modify - UEdGraphSchema_K2::RecombinePin

UE - Gameplay - Blueprint - Sep 7, 2017

This is a somewhat common crash affecting users in 4.17. Users have not provided any descriptions of their actions when the crash occurred. Source Context 606 void UEdGraphPin::AddStructRe ...

InstancedStaticMesh displaying corrupt lightmap data

UE - Graphics Features - May 17, 2021

I think I narrowed this issue down to bad UV coordinates being interpreted during the BasePassVertexShader execution applied to instancing. At this line in VertexFactoryGetInterpolantsVSToPS: flo ...