[Groom] Very thin hair has incorrect raytraced shadow on edges

UE - Graphics Features - Lumen - Jun 8, 2020

This only happens when 1) Hair Width is very small. e.g. 0.01 in the example 2) Light has raytraced shadow and Samples Per Pixel has a value > 1. e.g. 8 in the example The problem seems to be rel ...

Client and server can both get stuck waiting for packet sequence history flush

UE - Networking - Sep 4, 2025

The issue occurs when both instances have a significant difference between their last sent and last ack'd sequence number, as they will begin waiting for the sequence history to be flushed for a pac ...

Twinmotion sign-in error when attempting sign-in inside app

TM - Core - May 18, 2026

Reported in SF [Link Removed] Attempting to sign into Twinmotion from within the TM 2026.1 editor results in a consistent sign-in error using the sign-in buttons. Initial sign-in during launch whe ...

Adding SmartObjectZoneAnnotationComponent to a blueprint actor causes a crash when building the package

zComponent - Archive - Jan 30, 2025

If placing an actor with SmartObjectZoneAnnotationComponent added to blueprint actor in a level, it will crash when the level open. As a workaround, adding SmartObjectZoneAnnotationComponent to the ...

Spline don't deform landscapes in certain setups

UE - LD & Modeling - Terrain - Landscape - Dec 26, 2019

The splines do not deform the landscape when the path is made with a straight spline. When you move a spline point to bend the road it will deform the landscape, but the deformation accuracy seems t ...

Able to scale Math Hall graphs down to 0 which distorts them in ContentExamples

Docs - Samples - Sep 19, 2016

All of the graphs in the Math_Hall can be scaled down to 0 which causes the graphs to appear distorted. These should probably be clamped as 1 since scaling them down to 0 does not show any useful in ...

Modifying a Static Mesh's "Y" Collision Rotation also modifies "X" and "Z" Rotation

UE - Gameplay - Dec 12, 2016

If the user modifies the "Y" Rotation value of a Static Mesh's Collision, the "X" and "Z" values are changed. The values will move +/- 1 point from their value prior to modifying the Y value. This ...

Possible crash reimporting destructible assets

UE - Simulation - Physics - Destruction - Jan 20, 2017

This won't always happen, but the call in ImportDestructibleMeshFromApexDestructibleAsset to LODModel.ReleaseResources(); will enqueue render commands to release the resource, but the call after tha ...

Blueprints with inherited Macros cannot save

UE - Gameplay - Blueprint - Feb 27, 2015

Blueprints with inherited Macros cannot save. Reproduced in 4.7.1 binary and Main (//depot/UE4/Promotable-CL-2455917) ...

If using High Quality Gaussian DoF on Mobile, the whole screen is always blurred

UE - Platform - Mobile - Jun 17, 2020

When High Quality Gaussian DoF on Mobile is enabled, the entire screen is always blurred.  I confirmed that it works properly in 4.24. Also, I confirmed that adding the modified CL of [Link Remove ...