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 - Visual - 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 - Visual - 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 ...

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 - Visual - 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 - Core - 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 ...

Geometry Collection cluster handles leaking and causing ensures with field systems

UE - Simulation - Visual - Aug 26, 2025

Geometry Collection cluster handles leaking and causing ensures with field systems. The licensee has shared their analysis: We have been tracking down an assert that seems to happen occasionally wh ...

GeometryCollectionPhysicsProxy::FieldParameterUpdateCallback() not removing invalid Commands, leading to performance issues

UE - Simulation - Visual - Aug 30, 2025

GeometryCollectionPhysicsProxy::FieldParameterUpdateCallback() not removing invalid Commands, leading to performance issues. The licensee has provided their analysis: We seem to have stumbled acro ...

A Skeletal Mesh simulating physics that hits a Geometry Collection Actor with OneWayInteraction true, OneWayInteractionLevel 1, and is using Damage Propagation (default) will be accelerated so fast it immediately disappears by hitting the world limits

UE - Simulation - Core - Jan 20, 2025

A Skeletal Mesh simulating physics that hits a Geometry Collection Actor with OneWayInteraction true, OneWayInteractionLevel 1, and is using Damage Propagation (default) will be accelerated so fast ...

HighResShot Alpha always 255

Expected behavior is that screenshot alpha should be 0 for pixels that did not have anything rendered into them. ...