Unreal Engine Issues
Unreal Engine Issues
Artifacts appear on translucent particle systems during camera motion blur
UE - Rendering - Architecture - Jul 23, 2025Translucent particle systems exhibit visual artifacts when the camera moves, even though motion vectors are disabled for the particle emitters. While switching the Translucency Pass to "After Motio ...
ACineCameraAttachMount's "Target Actor" constraint does not work with Spawnables or Replaceables in Sequencer
UE - CAPT - Tools - Virtual Camera - Aug 12, 2025Constraints (UTickableConstraint) are usually created throuh the "Animation" tab available in the Editor's "Animation Mode". When created through that interface while Sequencer is open, the internal ...
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, 2025Copying 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, 2025Context: 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, 2025The 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 - AI Workflows - UI Systems - Nov 4, 2025When 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, 2025Function 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 - Verse Class Editor - Nov 12, 2025[Link Removed] Closed was fixed by CL 46990575, successfully avoiding an ensure condition inside FIntervalStructCustomization::S ...
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 - Runtime - Character - Dec 16, 2025Context: 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 ...
Editor ensure in USceneComponent::OnComponentDestroyed during Blueprint compilation GC
UE - Framework - Components - Jan 15, 2026An editor-only ensure can trigger during BP compilation when garbage collection cleans up transient components created as part of component replacement. During recompilation, old component instances ...