Unloading a spawned Detour AI Controller using Level Streaming causes a crash

UE - AI - Oct 14, 2019

In a Level Streaming setup, unloading a level that has spawned an AI Character with a Detour AI Controller causes a crash. This was reported and tested in 4.23 (CL-8386587). This was reproduced in ...

Issues with translucent material when using sceneColor node.

UE - Graphics Features - Oct 11, 2019

Issue seems to be linked to Eye Adaptation. Turning it off results in the sphere to be invisible. The attached image shows the output of the editor versus game mode (cooked or -game) This shader w ...

FMatrix::ErrorEnsure(const TCHAR* Message) doesn't output TCHAR parameter

UE - Foundation - Core - Oct 30, 2019

FMatrix::ErrorEnsure(const TCHAR* Message) doesn't output the message passed to it.  Found in 4.23 CL#9631420 Reproduced in 4.22.3 CL#7053642, 4.24.0 CL#9892386, 4.25 Main CL#9892271 ...

Duplicating two nested components do not appear in the Component tree until the blueprint is compiled.

UE - Gameplay - Components - Oct 23, 2019

REGRESSION: No, this occurs as far back as 4.22. Duplicating two nested components can result in the duplicates not being visible in the component tree in the blueprint editor until the user compil ...

Niagara Ribbon Facing Mode Custom Side Vector does not work correctly

UE - Niagara - Feb 28, 2020

The Custom Side Vector facing mode is no different than the Custom facing mode on Niagara ribbons. The linked UDN has more information on a potential cause, as well as a proposed fix. It looks like ...

An array of structures variable has its values reset when the structure is modified without recompiling the blueprint

UE - Framework - Blueprint Compiler - Apr 2, 2021

An array of a structure that has been modified without the array's blueprint being complied results in the values of the array element being reset. Compiling each blueprint that has the array of str ...

Dark square appears in hair in direction of spotlight when shadows disabled

UE - Graphics Features - Sep 18, 2024

A dark square appears in the direction of a spotlight on hair when the spotlight has no shadow. [Image Removed] In UE 5.4 the dark square is visible when the spotlight has no shadow, and a light s ...

No warnings or errors if a UEnum has Bitflags metadata, but no Flags flag.

UE - Framework - Blueprint Compiler - Jan 29, 2025

The problem here isn't obvious: the native enum, EAnotherEnum, is missing the Flags flag for the UEnum. As a result, K2Node_GetEnumeratorNameAsString returns the max enum when it gets a combined fla ...

Additives using Frame From This Animation as the Base Pose Type fail to retarget correctly

UE - CAPT - Retargeting - Feb 13, 2025

Additive animations that use a frame from their own sequence as a base pose are initially broken when retargeted.  Users have to refresh the properties that select the base pose in order to fix the ...

Actors transforms broken in cooked builds when their parent is an IsEditorOnlyActor

UE - Framework - Oct 7, 2025

When creating a hierarchy of Actors in the Outliner, the transform of the "child" actors will be reset if their Parent's IsEditorOnlyActor property is true.  The project in the EPS case is using ...