Metal crash after painting 300 Foliage meshes onto a surface

UE - Graphics Features - Oct 4, 2017

Encountered a Metal crash when painting Foliage on Mac. I'm unable to reproduce anything similar on Windows. This crash can occur if the user drags a Static Mesh into the Foliage Panel or uses an e ...

[CrashReport] ULevel::GetWorldSettings - UStaticMeshThumbnailRenderer::Draw

Tools - Oct 30, 2017

This is a common crash that has occurred since at least 4.14. The callstack is nearly identical to [Link Removed], which appears to be fixed in 4.18; and [Link Removed], which has not. The differen ...

Importing FBX creates new materials when using the search materials import setting

UE - Editor - Content Pipeline - Import and Export - Nov 1, 2017

There is an issue when importing FBX that creates new materials when using the search materials import setting. Instead of being able to use the material that is in the Base Material name, the textu ...

Volumetric fog does play nice with dynamic res

UE - Graphics Features - Jan 4, 2019

Dynamic resolution dynamically changes the the size of the viewport in render targets. The thing is when the resolution changes: it is reprojecting previous frame that is stored in history render ta ...

Asset localization does not work properly for Paper2D related assets such as Flipbook

UE - Core - Systems - Mar 18, 2022

This issue is resolved by changing Paper2D's LoadingPhase to PostConfigInit, but this is a workaround. We suggest a better long term fix via AssetRegistry changes (see comments). In the default la ...

Pose watches don't display correctly with compatible skeletons

UE - Runtime - Anim BP - Aug 19, 2022

"Hello, we've found a quirk with ABP's pose watch and compatible skeletons. Same setup as above. We have skeleton A as the base and skeleton B as a compatible skeleton. They both share similar hiera ...

Iris - large fast arrays serialize multiple elements when only one is dirtied

UE - Networking - Iris - Apr 8, 2025

This seems to be a result of how the changemask is handled for fast arrays. Because the changemask is a fixed set of bits (defined by IrisFastArrayChangeMaskBits), a single bit can represent multipl ...

The hierarchy of Actors in LevelInstances can break when using BPs as parent

UE - World Creation - Worldbuilding Tools - Level Instances - Feb 18, 2026

The hierarchy of a LevelInstance actors (Outliner) will break when cooking. The source is the call to AActor::RerunConstructionScripts in FWorldPartitionLevelHelper::MoveExternalActorsToLevel. The ...

When typing Korean in Slate using FTextInputMethodContext, characters outside a specific range are not entered

UE - AI Workflows - UI Systems - Slate - Apr 7, 2026

Descriptions After getting the below message LogTextStoreACP: Verbose: GetTextExt - From 33 to 34 A line break past that range is inserted. However, when typing Korean, the correct range is not s ...

Crash when adding multiple collision types to a mesh

Tools - Jan 27, 2017

Adding various collision types to a single mesh will cause it to hard crash the editor. No Crash Reporter window will open. Note that this happens with the user's mesh, but I was not able to repro ...