Wolrd Partition Foliage Builder - Fails to build with multiple external actor folders.

UE - World Creation - Worldbuilding Tools - World Partition - Apr 1, 2025

Hello, We are building a world with world partition & a lot of nanite foliage. We want to modify out Foliage Instance grid size via the commandlet. [Link Removed] Even in a new empty level the c ...

Invalid GUIDs on new material instance parameters cause overrides to break on base param rename

UE - Rendering Architecture - Materials - Sep 3, 2025

When a parameter value is assigned on a newly created material instance (constant or dynamic) using Set***ParameterValueInternal, the parameter’s ExpressionGUID is left invalid (0,0,0,0). Parameter ...

AbilitySystemComponent::NotifyAbilityEnded Can Crash due to Callbacks Invalidation Specs

UE - Gameplay - Gameplay Ability System - Oct 11, 2023

Pasting from the UDN: Unsafe code in AbilitySystem can lead to crash when granting an ability inside OnAbilityEnded Hello. We just ran into a crash. After investigation, it seems to be caused by ...

Landscape renders default material if apply another material instance under ES31 preview

UE - LD & Modeling - Terrain - Landscape - Aug 27, 2019

In ES3.1 preview, Landscape will render default material if change landscape material by using material instance of landscape's material. Will render correct if using another material's instance ...

Engine Crashing with AMD R9 2 and 3 Series Cards

UE - Graphics Features - Sep 23, 2015

Multiple users are reporting crashes in the Engine when using an AMD R9 380 and 390 series cards. There was a request to have these cards added to compat lab for testing, but have not heard any upd ...

Packaging a runtime plugin in a Blueprint project causes some Editor files to be deleted

UE - Foundation - Cpp Tools - Oct 22, 2018

Attempting to package a runtime plugin (does not occur with a Development plugin) in a Blueprint project fails in 4.21 Preview 2. This also causes some Editor files to be deleted, including the Modu ...

[CrashReport] UE4Editor_Engine!operator new<FBatchedLine,FDefaultAllocator>() [array.h:2812]

OLD - Anim - Jun 2, 2016

Error message: Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 804] Array index out of bounds: 175 from an array of size 171 Source Context: 2797 2798 temp ...

Engine/Extras/MayaLiveLink not provided in install directory

OLD - Anim - Nov 19, 2018

According to the Maya Live Link documentation, the zip file should be provided in the engine installation. https://docs.unrealengine.com/en-us/Engine/Animation/Live-Link-Plugin/Connecting-Unreal-Eng ...

5.3 crashes when loading a map with an actor that had the class of one of its components changed

UE - Gameplay - Components - Feb 1, 2024

Create a blueprint based on actor, give it a SceneComponent named ExampleComp (BP_TestActor) - this should be the blueprints only componentCreate a new level (TestMap), place an instance of the bluepr ...

Updating Material does not update platform stats in derived Instance

UE - Rendering Architecture - Materials - Nov 26, 2024

It would seem that updating a material does not update the associated platform stats in a material instance editor, only the parameters. Can workaround by manually invoking shader compile in the ma ...