ULevelInstanceSubsystem::CreateLevelInstanceFrom() is not honoring parameters bAlwaysShowDialog and LevelPackageName

UE - World Creation - Worldbuilding Tools - Level Instances - Aug 6, 2025

A Level Instance or Packed Level Actor can be created through editor scripting by using function ULevelInstanceSubsystem::CreateLevelInstanceFrom(), which receives parameters packed in the FNewLevel ...

Environment Query System (EQS): EnvQuery runtime template object can be created with a non-unique name, corrupting the EnvQueryManager cache

UE - AI - Aug 5, 2025

On file [Engine\Source\Runtime\AIModule\Private\EnvironmentQuery\EnvQueryManager.cpp:812], function UEnvQueryManager::CreateQueryInstance() uses StaticDuplicateObject() to create a new UEnvQuery* (d ...

Crash when changing parent of Material Instance with Layered Materials and viewing Layer Parameters

UE - Rendering - Architecture - Materials - Aug 1, 2025

Reparenting a MaterialInstance that uses Material Layers to another instance with a different layer configuration can cause the editor to crash when opening the Layer Parameters tab. This appears to ...

If any light source is deleted, and a single light has its visibility state changed in LightMixer, all the other lights in the scene that were invisible turn visible

UE - Virtual Production - Tools - Jul 31, 2025

If any light source is deleted, and a single light has its visibility state changed in LightMixer, all the other lights in the scene that were invisible turn visible. The behavior only shows after d ...

The LightMixer window is making all scene lights visible once you toggle the visibility of a single light

UE - Virtual Production - Tools - Jul 31, 2025

The LightMixer window is making all scene lights visible once you toggle a single light as visible. Any light source (except SkyLight) will be turn visible once a single light is made visible using ...

Hardware Raytracing on Lumen can cause a crash on AMD Radeon GPUs

UE - Rendering - Graphics Features - Lumen - Jul 29, 2025

Hardware Raytracing support can cause a crash on AMD Radeon GPUs when creating the RT pipeline state. ...

Artifacts appear on translucent particle systems during camera motion blur

UE - Rendering - Architecture - Jul 23, 2025

Translucent particle systems exhibit visual artifacts when the camera moves, even though motion vectors are disabled for the particle emitters. While switching the Translucency Pass to "After Motio ...

Unable to change Actor Coloration View Modes in PIE

UE - World Creation - Worldbuilding Tools - Jul 20, 2025

When in PIE changing Actor Coloration view modes from the viewport visualisation mode [Liit] -> [Actor Coloration] -> ... Does not update correctly when switching view mode and sometimes isn't corr ...

TInstancedStruct used in native actor class loses reference to Instanced UObject after BP recompilation

UE - Framework - Blueprint Compiler - Jun 25, 2025

When a TInstancedStruct contains a UObject marked with EditInlineNew and DefaultToInstanced, the reference is lost after compiling the Blueprint but only when the struct is part of a native Actor cl ...

Instanced Static Meshes ignore max World Position Offset Displacement for bounds after UpdateInstanceTransform is called

UE - Rendering - 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 ...