MoviePlayer loading screen with FLoadingScreenAttributes::bAllowEngineTick results in high DeltaSeconds tick post-playback

UE - Framework - Feb 16, 2024

IGameMoviePlayer playback of a movie during loading screen lets you set bAllowEngineTick  = true as a parameter. This will make FDefaultGameMoviePlayer manually tick the engine: if (GEngine && bAll ...

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 ...

FBX Camera Import into Sequencer - Scale Does Not Apply to Scene-Dependent Attributes (e.g., Focus Distance)

UE - Anim - Sequencer - May 1, 2025

When importing an FBX camera into a Level Sequence via the FBX Import dialog, we rely heavily on the Import Uniform Scale and Convert Scene Unit options for DCC interoperability. These settings ...

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 ...

AddComponent node fails to be scheduled after adding an "expose on spawn" variable to an ActorComponent-based Blueprint Class.

UE - Gameplay - Blueprint - Nov 13, 2015

If an existing AddComponent node is placed in an Actor Blueprint's Event Graph for a custom ActorComponent-based Blueprint Class, the node will fail to be scheduled after adding a variable marked "E ...

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 ...

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 ...

Editor Crashes When Using Set Replicates in the Construction Script

UE - Networking - Mar 1, 2016

When spawning an actor using the Spawn Actor From Class node that has a Set Replicates node in the construction script, the editor crashes upon attempting to run a dedicated server with 2 players. ...