StableSpringsSystem has lots of warnings

UE - Runtime - Deformable - Apr 6, 2026

System successfully compiled with 16 warnings. /Engine/Generated/NiagaraEmitterInstance.ush:2732:250: note: variable 'OutMaterialMultiplier' is declared here void SolveDistanceSpringMaterial_Emitter ...

Collections reset when the engine upgrades project

UE - Editor - Content Pipeline - Content Browser - Jul 8, 2015

When you upgrade your project to a new version of the engine, your Collections are deleted from the Collection setting. ...

EQS Generators named "NewBlueprint" cause errors and crash

UE - AI - Feb 11, 2015

Naming an EnvQueryGenerator_BlueprintBase derived BP "NewBlueprint" and deleting it causes new custom generators to not appear in the EQS. This can also lead to a crash when searching for the new ge ...

External Reference Spam when converting projects to 4.9

UE - Foundation - Core - Cooker - Sep 1, 2015

Map Check message log gets spammed with External Reference warnings when a project is converted to 4.9 from a previous engine version. These warnings don't seem to actually do anything to projects o ...

When using Lighting Scenario, loading order will affect how it's applied to the instances

UE - World Creation - Worldbuilding Tools - Foliage - Mar 7, 2019

When using Lighting Scenario, loading order will affect how it's applied to the instances, resulting in corruption if content is loaded after the lighting scenario ...

Orthographic Rendering - Lumen Reflection Artefacts

UE - Rendering - Architecture - Apr 28, 2023

Mutable custom versioning issue from 5.5->5.6

UE - Anim - Mutable - Sep 19, 2025

In 5.6, a handful of new entries in `FCustomizableObjectCustomVersion` were added, including `SetDisplayNamePropertyAsPinNameOfTableNodes`. Looking back at the history, `SetDisplayNamePropertyAsPinN ...

CSM has artifacts if shadow distance less than 2000

UE - Graphics Features - Jun 12, 2019

DoesSocketExist always returns false for Sprite Sockets (flipbooks and sprite components)

UE - Gameplay - Paper2D - Jan 15, 2015

DoesSocketExist always returns false for Sprites in a Flipbook, whether there is a socket on any/all of the Sprites or not. Note: GetSocketLocation seems to work fine, indicating that it is reading ...