Blueprint with instance static mesh from construction script will cause crash when using the build then build geometry

Tools - Mar 12, 2015

When using a BP with component instance static mesh that is added via the construction script, when using the build button in the toolbar to build lighitng and geometry everything will work correctl ...

OFPA Localizable Text Instances are not gathered when world partitioning is disabled

UE - Engine Scaling - Streaming - OFPA - Mar 7, 2025

Context One File Per Actor (OFPA) reduces overlap between users by saving data for instances of Actors in external files, removing the need to save the main Level file when making changes to its Act ...

Mover | FStanceModifier adjustment teleport on Crouch/Uncrouch can fail when child components intersect world

UE - Runtime - Character - Feb 3, 2026

Context When crouching and uncrouching with Mover’s DefaultMovementSet, the pawn capsule’s half height is changed. This behavior mimics the CharacterMovementComponent. To ensure the pawn’s feet sta ...

Adding OnClicked to SButton in Editor Mode plugin crashes editor when accessing the plugin

UE - Foundation - Cpp Tools - Plugin System - Mar 16, 2016

If a new editor plugin has a button added with OnClicked functionality, the editor will crash immediately when accessing the plugin. Removing the OnClicked portion of code allows the plugin to be a ...

NPC - Does not get updates from Material Parameter Collection changes in the editor

UE - Rendering - Architecture - Niagara - Sep 30, 2024

When an MPC is selected as the Source Material Collection for an NPC, all of its current parameters are carried over to the NPC with their current values. After that, if parameters are added to, rem ...

Lightmass Build Hanging at Specific Percentages

UE - Graphics Features - Sep 4, 2015

Lighting will build indefinitely in certain circumstances and can be verified in Swarm Agent that it will continue to process the maps even though the log shows it has completed. This is happening i ...

Lightmass Build Hanging at Specific Percentages

UE - Graphics Features - Sep 11, 2015

Lighting will build indefinitely in certain circumstances and can be verified in Swarm Agent that it will continue to process the maps even though the log shows it has completed. This is happening i ...

[bug] OIT doesn't work correctly with alpha composite blend mode

UE - Rendering - Features - Shading Models - Mar 4, 2025

When using OIT, AlphaComposite Materials blend as if they are using the Translucent BlendMode. The order of macro #if … #elif cases cause AlphaComposite Materials to take the same route as Transluce ...

Granular Synth crashes project when played in standalone or packaged with assertion failure

UE - Audio - Jan 5, 2021

Assertion failed: SoundWave->GetPrecacheState() == ESoundWavePrecacheState::InProgress The above assertion fail was seen when played in standalone mode. Play-In-Editor mode (PIE) is working as exp ...

Nanite displacement issue when using along non-uniform scaling

UE - Rendering - Features - Nanite - Feb 26, 2026

Nanite Tessellation displacement direction is incorrect for landscapes with non-uniform scales. It seems to use the normal from the unscaled landscape, which can result in the displacement causing t ...