Niagara mesh particles have incorrect normals when scaled

UE - Niagara - Apr 27, 2020

Niagara mesh particle normals do not match those of static mesh actors. ...

Transition ratio getter function not correct for interrupted transitions.

OLD - Anim - Apr 7, 2016

The transition ratio getter simply uses ElapsedTime/Crossfade for the alpha on the transition. Normally this is sufficient, although if you blend between two states A and B such that you interrupt ...

Material attribute layers issue with texture sample and VT lookups

UE - Rendering Architecture - Materials - Nov 14, 2024

When using material attribute layers in a material layer setup, there is a potential discrepancy in the number of VT Lookups presented in the material instance's Platform Stats. When the same textur ...

Dynamic NavMesh disappears when loading/unloading SubLevels

UE - AI - Nov 9, 2018

A DynamicNavMesh within a NavMeshBoundsVolume placed in a SubLevel will disappear if loading/unloading another SubLevel that has completely nothing to do with the DynamicNavMesh. Using a setup with ...

Unreal Header Tool can sometimes fail if an Engine plugin is Enabled By Default and has the "Program" Module Type set

UE - Foundation - Core - Feb 15, 2018

An Engine plugin with the Program module type and EnabledByDefault set to true can cause the Engine to fail to build successfully due to UHT failing. I was only able to reproduce this behavior using ...

Gameplay Tags with the string "None" as any of its hierarchical node identifiers behave incorrectly (because of an incomplete generated FGameplayTagContainer::ParentTags array)

UE - Gameplay - Nov 19, 2024

Currently, using the string "None" as a hierarchical node identifier inside a Gameplay Tag (for example "A.B.C.None.D.E.F") is not disallowed by the engine, but results in some incorrect behaviors. ...

Widget "Listen For Input Action" executes on unexpected input event

UE - Editor - UI Systems - Feb 19, 2020

Listen For Input Action firing erroneously. Confirmed in 4.26 MAIN @ CL 11536993 ...

Mutable constant texture variable with ClipUV mask only works with new experimental dynamic variable is connected as well

UE - Anim - Mutable - Sep 22, 2025

We are attempting to use Mutable in 5.6.1 and have encountered an issue which we are not sure how to resolve. The issue occurs when using the ClipWithUVMask node. In short we have a customizable o ...

Changing the state of a PrimitiveComponent->BodyInstance while SetSimulatePhysics(false) updates the game thread but does not update the physics behavior

UE - Simulation - Physics - Nov 21, 2024

Changing the state of a PrimitiveComponent->BodyInstance while SetSimulatePhysics(false) updates the game thread but does not update the physics behavior. In the repro project provided (see addl in ...

Shortcuts do not appear to work for the visual logger

UE - AI - Nov 16, 2017

Shortcuts do not appear to work for the visual logger in the editor preferences ...