Non-existing config file loading could cause memory leak

UE - CoreTech - Oct 19, 2023

The cause of this problem is the Engine has code paths which register a new allocated object to Map without deleting the previous object. In the repro project, whenever hitting Space Bar, the level ...

Crash when calling SetState inside state machine OnUpdate

UE - Anim - Sep 5, 2025

The crash happens when SetState is called inside the function bound to OutputAnimationPose’s OnUpdate in the animation state. This way of using Set State node is the same as shown in the official do ...

Chaos Trailing Events not exposed to Blueprints and only accessible via Niagara Chaos DI

UE - Simulation - Physics - Destruction - Apr 22, 2025

Chaos Trailing Events not exposed to Blueprints and only accessible via Niagara Chaos DI. The licensee noticed that the Trailing event is not available to BPs. It's expected that the same data avail ...

UNetDriver server-side hitch results in ActorInfo->NextUpdateTime far into future

UE - Networking - Feb 16, 2024

A high UWorld::Tick DeltaSeconds (i.e. GameThread hitch) results in a high UNetDriver::TickFlush DeltaSeconds. This DeltaSeconds can high (many seconds) if the hitch is long. This value then affects ...

The Remove-On-Break feature, set on Fracture Mode on Geometry Collections, stops shrinking and shows strange behaviors

UE - Simulation - Physics - Destruction - Oct 15, 2024

The Remove-On-Break (ROB) feature, set on Fracture Mode on Geometry Collections (GC), was supposed to make the particle shrink until it vanishes. When the GC goes to sleep the shrinking stops and sh ...

Unexpected corrections when sliding against other characters

UE - Gameplay - Player Movement - Oct 19, 2023

We are seeing unexpected movement corrections sometimes when pushing one player character up against another character that isn't moving, or against other static primitives that have round features ...

A GeometryCollection that was broken and is going through shrinking will reset the size of its particles if a second level is broken

UE - Simulation - Physics - Destruction - Oct 18, 2024

Might relate to issue [Link Removed] - "The Remove-On-Break feature, set on Fracture Mode on Geometry Collections, stops shrinking and shows strange behaviors" The added information on this particu ...

Calling BodyInstance.UpdateBodyScale displays erratic behaviors and does not update the rendering scale

UE - Simulation - Physics - Nov 22, 2024

Calling BodyInstance.UpdateBodyScale displays erratic behaviors and does not update the rendering scale. The licensee has reported and presented a repro project that displays the erratic behavior of ...

Dithered LOD transitions sometimes briefly flicker to the next LOD before fading

UE - Graphics Features - Jun 12, 2025

When dithered LOD transitions occur, a brief flash of the next LOD level is first shown on the entire mesh after which the current LOD fades to the next (or previous) LOD. The flashing behavior only ...

Dithered LOD transitions do not work when the camera's field of view changes

UE - Graphics Features - Jun 12, 2025

Dithered LOD transitions do not work when changing the camera's field of view and cause artifacts when both the FOV and camera distance to the object are changed simultaneously. ...