DrawDebug elements on screen affect aspect ratio letterboxing

UE - Rendering Architecture - Nov 1, 2023

During gameplay when the view target camera's aspect ratio is not exactly the viewport's aspect ratio, the presence of rendered debug draw elements (DrawDebugArrow, etc) makes the viewport's rendere ...

Copy Actors out of play mode ( 5.3.1 )

UE - Editor - Workflow Systems - Dec 22, 2023

From UDN case #00645621: Is it possible that this function has been deactivated? In 5.03 I can copy objects from the game mode. ...

Translucent Materials no longer reflect light when using Forward Lighting variable

UE - Graphics Features - Jun 7, 2016

Translucent materials are no longer showing light reflections in scene when using r.forwardlighting 1 with lights. This is a regression from functionality in 4.11.2. This no longer works with 4.12 ...

Server RPC with struct param containing class reference does not pass parameter

UE - Networking - Apr 2, 2018

Class ref is not passed to server within the struct in UE 4.19. Instead, the default value is passed to the server. LogNetPackageMap: Warning: SanityCheckExport: CacheObject == NULL. NetGUID: 1, Ob ...

Incorrect shading for SubSurface profile in the Blueprint Viewport.

UE - Graphics Features - Dec 30, 2016

The Subsurface shading looks incorrect in the Blueprint Viewport window. Adjusting the cvar for r.sss.checkerboard from the default value of 2 to 1 looks more correct and a value of 0 switches back ...

Invalid Landscape Normals at component boundaries and subsections In Packaged Build

UE - Graphics Tools - Terrain - Oct 31, 2025

In UE 5.6, heightmap texture compression was introduced. The original implementation did not consider duplicate pixels along subsection and shared textures (multi-component) boundaries. As a result, ...

Editor Crashes when importing some FBXs with multiple Material IDs in 4.14.2

UE - Editor - Content Pipeline - Import and Export - Jan 5, 2017

This is a regression in behavior between 4.14.1 and 4.14.2! The editor will crash when importing FBX meshes that have multiple material ID assignments. If it's a single material ID it will import w ...

Random Number Generated in Constructor Returning Different Value on Begin Play

UE - Gameplay - Jan 13, 2016

When generating a random number using FMath::RandHelper() in the constructor of an actor, attempting to print that same number on BeginPlay returns a different value than the constructor. However, ...

Particles Do Not Obey Lighting Channels

UE - Niagara - Apr 17, 2018

Particle systems ignore lighting channels - no matter what channel a light is on (even if no channels are selected), it will affect lit particles. Changing lighting channels on the particle itself h ...

Crash with FBX with LODs when distance fields and Generated Lightmaps are enabled

UE - Graphics Features - Jan 12, 2015

DESCRIPTION: When importing a mesh with 1 or more additional LODs when Generate Mesh Distance Fields has been enabled via the Project settings will cause a crash if the import options include using ...