Copying a grouped MaterialInstanceParameterDetail property that has spaces on it's name does not enclose it in double quotes, and later pasting won't work as expected

UE - Rendering Architecture - Materials - Aug 24, 2025

Copying a grouped MaterialInstanceParameterDetail property that has spaces on it's name does not enclose it in double quotes, and later pasting won't work as expected. The licensee noticed this in a ...

Landscape Textures Patches issue when using "Texture Backed Render Target" as the Height Patch Source Mode where Landscape patches are not applying properly the first time a level is opened after restart

UE - Graphics Tools - Terrain - Landscape - Oct 6, 2025

Context: Landscape patches are components that can be attached to meshes to affect the landscape as the mesh is repositioned. Problem: The problem is that when using "Texture Backed Render Target" ...

Niagara crash when using a particle attribute reader that has been passed around between modules

UE - Niagara - Oct 28, 2025

The following Niagara usage pattern results in either a crash or in incorrect data being read from a Particle Attribute Reader: Emitter Spawn Stage – A module has an Attribute Reader input specifie ...

UMG: RetainerBox with zero-size child returns incorrect LayerId on OnPaint()

UE - Editor - UI Systems - Nov 4, 2025

When a RetainerBox contains a child that for some reason has a desired size of zero, its OnPaint() method can incorrectly return LayerId 0. Afterwards, widgets further down the hierarchy can base th ...

Mover Plugin: UNavMoverComponent::GetFeetLocationBased() returns incorrect FBasedPosition when using WalkingMode over a Movable floor, making UPathFollowingComponent erroneously detect a blocked move

UE - Gameplay - Player Movement - Mover - Nov 12, 2025

Function UNavMoverComponent::GetFeetLocationBased() on file "NavMoverComponent.cpp" returns an FBasedPosition built from an FRelativeBaseInfo. The "MovementBaseInfo" is read from key "CommonBlackboa ...

Ensure triggered inside Range Struct Customization when Property Node is no longer valid (e.g. when editing FFloatRange while FRuntimeFloatCurve editor is visible) [Ref. UE-341339]

UE - Editor - Workflow Systems - Nov 12, 2025

[Link Removed] was fixed by CL 46990575, successfully avoiding an ensure condition inside FIntervalStructCustomization::SetValue() when its Property Node is no longer valid. However, the same proble ...

A chaos vehicle that moves at very high speeds with CCD enabled on the vehicle sometimes has a collision response that is abnormal where the vehicle loses a significant amount of speed when colliding with dynamic objects configured as One Way Interaction

UE - Simulation - Gameplay - Dec 16, 2025

Context: Continuous Collision Detection (CCD) is being used on a Chaos Vehicle to avoid tunneling issues with certain surfaces as it prevents any missed collisions between fast moving particles and ...

Plugin fails to compile in 4.11 due to redefinition errors

UE - Foundation - Cpp Tools - Plugin System - May 10, 2016

Plugin fails compile in 4.11 / 4.12 due to redefinition of class/struct type (locally). AH user reported LNK2005 error when compiling in 4.11 Regression: YES? - Project with the attached plugin co ...

Trigger Volume Blocks First-Person Template Projectile

UE - Simulation - Physics - Nov 2, 2015

When playing in editor, if you fire your weapon at a trigger volume, the projectiles will bounce off of the volume, regardless of the fact that the collision is set to Query Only. This collision als ...

Ragdoll Physics do not Function Properly on a Mirrored Skeletal Mesh

UE - Simulation - Physics - Dec 1, 2015

Selecting the default character/skeletal mesh (or any skeletal mesh) in the viewport, right-clicking and transforming it so it mirrors on the X,Y, or Z axis will cause the physics to act erratically ...