Cannot select child anim BPs for use in linked anim layers

UE - Anim - Runtime - Jul 15, 2021

From UDN: [Link Removed] Unable to set a Child ABP with inherited interface to a Linked Animation Layer Instance Class. I have a ABP_Biped which is our main ABP. I have the locomotion (idle+straf ...

Instanced Static Meshes ignore max World Position Offset Displacement for bounds after UpdateInstanceTransform is called

UE - Graphics Features - Jun 18, 2025

When an Instanced Static Mesh Component (ISMC) uses a material with a non-zero Max World Position Offset Displacement, the bounds are correctly expanded at initialization. However, after calling Upd ...

Crash on Adding Texture Samples with modified BasePassPixelShader.usf

UE - Graphics Features - Jul 27, 2015

In 4.8.2 QA Build - Making the changes to BasePassPixelShader.usf listed below, adding two texture samples and then using the Preview Arrow toggle on the add node will hard crash the CPU, requiring ...

Render target size mistmatch in ShaderDrawDebug

UE - Graphics Features - Jun 9, 2020

We found a d3d debug validation assert in RDG_EVENT_NAME("ShaderDrawDebug"), with the full DLSS integration. It however also reproduces in  (4.25.1-release, dev-rendering and the plugin branch with ...

Wrong density calculation in UBodySetup::CalculateMass

UE - Simulation - Core - Sep 29, 2025

Wrong density calculation in UBodySetup::CalculateMass. The licensee has provided the following analysis and suggested fix: In UBodySetup::CalculateMass, the following code is present: // physical ...

Always Relevant actor may replicate incorrect movement mode when the walkable floor becomes irrelevant

UE - Gameplay - Player Movement - Feb 26, 2024

When the character class is set to always relevant, if a client travels very far away from another character, such that the character is relevant but the component they're standing on is not (but al ...

Unwanted black boundaries are displayed in a vertical split-screen with 3 players.

UE - Gameplay - Dec 2, 2019

Floating point error from UGameViewportClient::SplitscreenInfo causes this issue. FMath::TruncToInt( 3240 /*ViewportSize*/ * 0.333f/*Ratio in SplitScreenInfo*/ ) = 1079 I suggested a following t ...

[CrashReport] UE4Editor_CoreUObject!StaticAllocateObject() [uobjectglobals.cpp:2153]

UE - Anim - Sequencer - Jun 3, 2016

Really close to the repro steps for [Link Removed] Same repro steps produced the following Buggs along with this one: [Link Removed] [Link Removed] Error message: Fatal error: [Link Removed] [Lin ...

After breaking a level instance without Actor Folders, moving its actors between folders of the world-partition map does not work correctly

UE - World Creation - Worldbuilding Tools - World Partition - Jan 29, 2024

If a standard level (without Actor Folders enabled) is added to a world-partition map (with Actor Folders enabled) as a Level Instance, and then that instance is "broken" so that its actors are inco ...

Destructible mesh does not trigger overlap event for objects/pawns that are not moving

UE - Simulation - Physics - Destruction - Dec 12, 2014

DESCRIPTION: When using the generate overlap events for a destructible mesh with Static Mesh or skeletal mesh that is not moving will not generate an overlap event to be triggered. So long as the me ...