Orientation Warping breaks incoming poses where bones are in component space

UE - Anim - Gameplay - Apr 17, 2025

The orientation warping node breaks incoming poses where bones are already in component space. This is because, in EvaluateSkeletalControl_AnyThread, we are repeatedly setting bone transforms direc ...

BP hierarchy change triggers incorrect map actor load warning: AttachTo: '{0}' is not static {1}, cannot attach '{2}' which is static to it.

UE - Framework - Blueprint - Apr 11, 2024

When a blueprint's component hierarchy is changed by changing a child component's mobility value to Static while deleting its parent component which has Movable mobility, levels saved with an outdat ...

Orphaned BP actors when using UWorldPartitionBuilder

UE - World Creation - Worldbuilding Tools - World Partition - Nov 21, 2025

From an EPS case: --------------------------------- We're seeing a recurring issue where child BP actors are becoming orphaned during any processing that uses UWorldPartitionBuilder. It affects ...

UnkownRef Mips can cause TextureStreaming peaks during loading

UE - Graphics Features - Mar 27, 2023

UnkownRef Mips is meant to fix/workaround the problem where some textures are used for rendering but they don't have any component references them (such as texture used by PP effects) These UnkownR ...

Inconsistent behavior with Register State Branches

UE - Editor - Workflow Systems - Aug 31, 2023

ISourceControlProvider::RegisterStateBranches(...) doesn't reliably warn on conflicts ISourceControlProvider::RegisterStateBranches(...), specifically FPerforceSourceControlProvider, is supposed to ...

Translucent Wireframe Materials Exhibit TSR Aliasing/Crawling Due To Incorrect Velocity Rendering When Set to Output Depth And Velocity

UE - Graphics Features - Nov 27, 2025

Note that this bug potentially also affects a wide variety of material / geometry setups; however, a translucent wireframe setup is currently the main reproduction case. The issue may also be notice ...

DataTable asset view runs out of (video) memory

UE - Editor - UI Systems - Slate - Feb 26, 2024

In some situation, Slate tries to secure incredible amount size data and run out of memory. This happens a cell having very long and complex serialized text appears on the editor and it is placed to ...

Conflict between sequencer transform track and Parent Constraint from the Animation Mode breaks temporary pivot translation on any actor

UE - Anim - Anim in Engine - Jul 15, 2025

Note: This affects all versions from at least UE 5.3, including mainline latest. The "Animation" Editor Mode allows creating constraints for level actors. One of these, the "Parent" constraint, con ...

Translucent materials in the PostMotionBlur pass can cause a flickering viewport artefact when using TAA

UE - Graphics Features - Feb 5, 2025

There appears to be a bug relating to rendering multiple windows that can trigger under unknown circumstances. It has been reported on rectangle lights in the forums and on PostMotionBlur materials ...

Velocity Scene Texture Data Integrity Issues

UE - Graphics Features - Jan 8, 2026

When a Post-Process Material uses the Scene Texture Material Expression, the following code is generated: ``` MaterialFloat2 Local0 = Parameters.TexCoords[0].xy; MaterialFloat2 Local1 = ClampSceneT ...