Running the BuildPlugin command results in a warning that ForceCompile is not supported and an error that an item with the same key has already been added

UE - Foundation - Cpp Tools - Automation Tool - Dec 7, 2022

Repro Rate: 5/5 This issue was encountered in the 5.1.0 live launcher build of //UE5/Release-5.1 at CL 23058290 and reproduced by other users. Regression tested against the 5.0.3 live launcher bui ...

Light Leak Issue in Modular Buildings (Lumen HZBTraversal)

UE - Graphics Features - Lumen - Oct 14, 2025

Starting in Unreal Engine 5.6, disabling "r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal" can lead to light leaking between adjacent or overlapping meshes. Also tested on Release-5.6, CL: 4523 ...

FBX naming conflicts causing collision to not import correctly.

UE - Editor - Content Pipeline - Import and Export - Feb 17, 2025

For our static mesh pipeline we have group nodes in Maya that use the name of the asset. Under that we have a mesh that also has the name of the asset. We may also have collision as well so a typica ...

Animation Rate Scale does not appear to have an affect when blending an animation with two different Rate Scales

OLD - Anim - Dec 14, 2018

Rate Scale does not appear to have an effect when using a blend space that blends an animation with two separate Rate scales. ...

4K Resolution and High DPI Scaling in Linux aren't completely affected by System Display Scaling

UE - Platform - Linux - Aug 26, 2019

Unreal doesn't change appearance when changing system configuration display scaling options. Editor Texts are still quite small and don't change based on the Display Scaling %. This bug also causes ...

Making a navigation system 'strictly static' affects all subsequently created navigation system instances

UE - AI - Mar 26, 2020

The problem is a result of two things: UNavigationSystemV1::bStaticRuntimeNavigation being staticUNavigationSystemModuleConfig::UpdateWithNavSysCDO copying the data from nav sys CDO, including bStat ...

When 1 AnimSequence asset is used for multiple SeuqnecePlayer, the override by AnimGraphOverrides affects other than the specified SequencePlayer.

UE - Anim - Runtime - Anim Blueprints - Jun 30, 2022

If you use the same AnimSequence in multiple SequencePlayers in Base AnimBP and replace asset of one of SequencePlayers by AssetOverride in Child AnimBP, the result will be reflected in the other Se ...

Transform Origin Scale on the Level Sequencce Actor's Instance Data can affect rotations

UE - Anim - Sequencer - Apr 30, 2025

Scale is used as part of the rotation calculation for transform multiplication, and it can have an effect in the sequence transform origins. It's expected that scale is completely ignored, and shou ...

A Skeletal Mesh simulating physics that hits a Geometry Collection Actor with OneWayInteraction true, OneWayInteractionLevel 1, and is using Damage Propagation (default) will be accelerated so fast it immediately disappears by hitting the world limits

UE - Simulation - Core - Jan 20, 2025

A Skeletal Mesh simulating physics that hits a Geometry Collection Actor with OneWayInteraction true, OneWayInteractionLevel 1, and is using Damage Propagation (default) will be accelerated so fast ...