Substrate Adaptive GBuffer: HWRT Hit Lighting drops indirect lighting from lights with a Light Function (GI / Reflections)

UE - Rendering - Features - Shading Models - Oct 22, 2026

The Light Function variant of the hit lighting miss shader is compiled as the Light Function material, so MATERIAL_IS_SUBSTRATE=1. This makes it read the ray hit surface from the payload incorrectly ...

Physics Constraint doesn't hold if one Component is used for constraint

UE - Simulation - Physics - Jul 22, 2015

Physics Constraint doesn't hold if one Component is used for constraint User Description: Hello, I recently updated the project from 4.7.6 to 4.8.2 and the physics constraint don't seem to work an ...

Crash while scrolling through language options in Packaging settings

Tools - Jul 21, 2017

This is a trending crash in the 4.17 preview. This is a regression Broken: 4.17.0-3528061 Worked: 4.16.2-3514769 User Descriptionsproject/settings/intern..language. Crashed it just by scrolling t ...

Virtualized Silent Sounds "Pop" When Played With New Mixer

UE - Audio - Sep 27, 2017

-Could not reproduce and only happens in the project linked below -Tested in 4.16 and Preview 4.18 and this can not be heard -Does not look like the .ini file is the cause of the issue -Other soun ...

UnrealVS: Compile Single File no longer working after upgrading to 5.3

UE - Core - Cpp Tools - Oct 2, 2023

After installing the UnrealVS version that arrived with 5.3. I can no longer use CompileSingleFile. It does however work on the Lyra project. One difference I notived, however, is that Lyra seems to ...

FAnimationRuntime::BlendPosesPerBoneFilter() causes an assertive crash when Skeletal Mesh LOD is changed

UE - Runtime - Animation - Nov 1, 2023

The crash occurs from "check(BoneBlendWeights.Num() == NumBones);" This crash occurs when the following conditions are met;The skeletal mesh LOD is changed.The number of bones is difference between ...

Unable to open UE4Editor on Linux - Bad hlslcc header found

UE - Platform - Linux - Nov 4, 2015

UE4Editor does not open on Ubuntu 15.10 due to the following error: [2015.11.04-16.19.35:974][ 0]LogOpenGLShaderCompiler:Error: Bad hlslcc header found! Missing '#'!Error in `./UE4Editor': free(): ...

Assertion failed: GEditor->GetSelectedActorCount() == 1 in FLevelEditorActionCallbacks::Paste_CanExecute

Tools - May 3, 2017

This is a high frequency crash occurring for our users. It appears to be the same crash reported in [Link Removed], however that was fixed in 4.15.0, and the specific repro steps are verified to no ...

VS fails to compile when USTRUCT is referenced as BlueprintReadWrite or BlueprintReadOnly

UE - Foundation - Cpp Tools - UnrealHeaderTool - Aug 22, 2017

Defining a FBoneReference variable as BlueprintReadWrite or BlueprintReadOnly in the UPROPERTY macro fails to compile in 4.17. The error message provided by VS states: LogCompile: Error: Type 'FT ...

Cannot package an Engine plugin if another Engine plugin depends on the plugin being packaged

UE - Foundation - Cpp Tools - Plugin System - Nov 12, 2018

Packaging an Engine plugin fails if another Engine plugin lists that plugin as a private dependency. In the two attached plugins, PluginA lists PluginB as a required plugin in its .uplugin file, and ...