A Geometry Collection with Removal-On-Break, after breaking and shrinking until vanished, will reset to the original state (full-size and unbroken) if we toggle between Fullscreen and Windowed while playing as standalone or Packaged Build.

UE - Runtime - Deformable - Oct 28, 2024

A Geometry Collection with Removal-On-Break, after breaking and shrinking until vanished, will reset to the original state (full-size and unbroken) if we toggle between Fullscreen and Windowed while ...

Blueprint function-local variable properties don't copy metadata from the source FBPVariableDescription

UE - Framework - Blueprint Compiler - Jan 23, 2025

FKismetCompilerContext::CreateUserDefinedLocalVariableForFunction() does not copy the metadata from the source FBPVariableDescription entry. Class variables work because there is code for that in FK ...

Lumen ignores Landscape Holes (Landscape Visibility) when Hardware Ray Tracing is enabled and Ray Lighting Mode is set to Surface Cache

UE - Rendering - Graphics Features - Ray Tracing - Jan 31, 2025

Context Lumen is the default global illumination and reflections system. Lumen renders diffuse interreflection with infinite bounces and indirect specular reflections in large, detailed environments ...

AllowAsyncRenderThreadUpdatesEditorGameWorld/AllowAsyncRenderThreadUpdatesEditor CVars are off by default and unsafe in Niagara

UE - Niagara - Mar 4, 2025

This user made a github pull request: [Link Removed] but it was auto rejected. I think that we can consider taking their fixes, but keeping it disabled by default. ...

When using Perforce, saving a level over another leaves the target umap file as "marked for delete"

UE - Editor - Mar 11, 2025

When working on a level asset and using command "File – Save Current Level As..." to save it over a different level asset, the engine first deletes the target level (that's going to be overwritten) ...

Moving a saved duplicate of an OpenWorld level crashes the Editor

UE - World Creation - Worldbuilding Tools - Mar 19, 2025

Moving a saved duplicate of an OpenWorld level crashes the Editor. The act of moving the duplicated OpenWorld level crashes the Editor the moment the engine tries to delete the original level, so it ...

Crash when exposing a TOptional<FName> or TOptional<FText> to the editor through a UProperty.

UE - Editor - Mar 25, 2025

Support for editor-exposed uproperties of type TOptional<T> has been added by CL 28199740 on september 2023. However, since then until today in UE 5.5, a crash can happen when exposing TOptional<FNa ...

Editor crash while saving asset during cook operation

UE - Core - Data Pipeline - Cooker - Apr 2, 2025

It is possible to experience an editor crash in 5.5.4 when the cook process generates a warning that references an asset while the editor is saving. It seems that during a save operation, the code t ...

UEditorValidatorBase::ValidateLoadedAsset() is not using the K2_ValidateLoadedAsset() output, effectively ignoring the Blueprint validation

UE - Editor - Content Pipeline - May 1, 2025

UEditorValidatorBase::ValidateLoadedAsset() is not using the K2_ValidateLoadedAsset() output, effectively ignoring the Blueprint validation. The K2Result is not used later in the function, and this ...

A partially broken Geometry Collection ends up with garbage CollisionGroup data that can lead to strange behaviors

UE - Runtime - Deformable - Apr 27, 2025

A partially broken Geometry Collection (GC) ends up with garbage CollisionGroup data that can lead to strange behaviors. The licensee has noticed that a GC that goes thru a field applying ExternalS ...