Setting PHYSX_MEMORY_STATS to 1 prevents the Engine from being built successfully.

UE - Simulation - Physics - Mar 9, 2015

If #define PHYSX_MEMORY_STATS 0 is set to 1, the Engine will not build successfully. The build fails with the message: error C2338: FPhysXAllocationHeader size must be less than 16 bytes. ...

Point lights with source length building static lighting in incorrect direction

UE - Graphics Features - Mar 21, 2018

There is an issue where Point lights with source length building static lighting in the incorrect direction, the axis in which the light to be built seem to conflict with the preview build. This iss ...

Subtraction Node wild card inputs incorrectly assigns Time Span data type when given a Date Time data type

UE - Gameplay - Blueprint - Nov 18, 2021

This is a regression //UE4/Release-4.27 has "DateTime - DateTime" and a "DateTime - TimeSpan" node. The subtraction node, with wild card inputs, incorrectly assigns Time Span data type when fed a D ...

Lighting Channels Do Not Function with 78+ Lights on Actor

UE - Graphics Features - Oct 20, 2017

Lighting channels do not function when the number of lights affecting actors is 79 or higher. Any number of lights that is 78 or fewer will honor lighting channel assignments. ...

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 ...

When Character BP actor is rotated, "Mesh" component translation differs on Client and Server

UE - Gameplay - Apr 21, 2015

Occurs in: Releases 4.7.6 CL:2510309 Main 4.8 CL:2513846 When Character BP actor is rotated, Translation is changed for "Mesh" component on Client. Server appears as expected. This isn't typicall ...

STAT_VolumetricLightmapBuildData is not counted correctly

UE - Graphics Features - Dec 9, 2022

STAT_VolumetricLightmapBuildData isn't counted correctly. It seems that the root cause is Volume.IndirectionTexture.DataSize is set to 0 before STAT_VolumetricLightmapBuildData is decreased.// Prec ...

Cannot resize comment box when new comment is created on top

UE - Rendering Architecture - Materials - Apr 27, 2017

Cannot resize comment box when a new comment is created on top. The resizing affects the bottom right corner. This issue is dependent on how the comment is added if comment 1 is highlighted and a ne ...

PerInstanceRandom does not work on Instanced Static Meshes spawned at runtime

UE - Graphics Features - Aug 11, 2017

PerInstanceRandom does not provide a random value when the material is being used on an Instanced Static Mesh that is spawned at runtime, the value is always the same. Regression?: Yes This did not ...

TArray64 RangeCheck prints the incorrect error messages for values over 32-bit length

UE - CoreTech - Apr 27, 2022

TArray64 RangeCheck prints the incorrect error messages for values over 32 bit. Repro Rate: 4/4 Tested this in //UE4/Release-4.27 @ CL#18319896 and the issue did occur there, it is not a regressi ...