Particles emit from corrupted positions when spawning from cloth vertex

UE - Simulation - Physics - Character - Aug 4, 2017

When spawning particles from skeletalMesh vertices(using Skeleteal Vert/Surf Location), if the specified mesh is a cloth, some particles appear away from the mesh itself. This happens in 4.16 and 4. ...

Projects cannot be built and opened in DebugGame from the commandline

UE - Foundation - Core - Oct 16, 2017

Code projects in 4.18 cannot be opened in DebugGame from the commandline. REGRESSION: Yes. This worked successfully in 4.17.2. The attached log is from 4.19. The log for 4.18 was similar. ...

When Importing Camera, Previously Imported Cameras' Focal Length is Overridden

UE - Anim - Sequencer - Dec 4, 2017

4.17 does not allow for camera import. If multiple cameras are imported into sequencer, all cameras Current Focal Length change to match the newest imported camera. Mentioning Jira: [Link Remove ...

Datasmith imports glossiness Texture as a Normal Texture

UE - Editor - Content Pipeline - Datasmith - Exporters - Sep 6, 2018

The Datasmith Importer for 4.20 (4.20E2) imports Glossiness Textures as Normal Maps. This is a regression from 4.19.2 (0.182) as Glossiness Textures were imported as World Textures ...

Private lobbies cannot be invited to on Steam

UE - Online - May 13, 2019

The old method doesn't work with private match invites as it doesn't have the right security permissions. It's still valid for dedicated servers. It also doesn't work properly with lobbies on VR eit ...

Montage Root Motion does not work from sub anim instances

UE - Anim - Gameplay - Oct 25, 2019

Root motion from sub instances is not used when the parent instance is marked as 'Root Motion from Montages Only'. Proposed fix is to modify USkeletalMeshComponent::IsPlayingNetworkedRootMotionMo ...

ISM Component in an instanced BP does not take into account changes to NumCustomDataFloats from the BP class

UE - Graphics Features - Sep 16, 2022

PerInstanceSMCustomData is bulk serialized and doesn't get changed on the BP instance when changing NumCustomDataFloats, possibly causing out of bounds array access leading to a crash. Possible sol ...

LOD ScreenSize per platform is not reflected in the mobile preview

UE - Platform - Mobile - Jan 31, 2023

in 5.0 or 5.1, MinimumLOD  per platform can be previewed in the mobile ES3.1 preview mode, but It seems that the LOD ScreenSize per platform is not reflected in the mobile preview. ...

Auto Exposure Compensation Curve issue when switching from Histogram to Manual

UE - Rendering Architecture - Feb 21, 2024

When switching the Camera's Exposure Metering Mode from Histogram to Manual, there is a single-frame flash. The Licensee has a proposed code change that would fix this issue. Also found in 5.4, CL 3 ...

Performance hitch from RemoveGeometryCache flushing the render thread

UE - Editor - Content Pipeline - Alembic - Jun 12, 2025

FGeometryCacheStreamingManager::RemoveGeometryCache calls FlushRenderingCommands which shows up as a hitch when profiling. [Link Removed] Ideally the flush added in CL#23782411 to fix a rare deadl ...