Assertion failed in FNetGUIDCache::CleanReferences during seamless travel after reloading primary asset package

UE - Networking - May 7, 2025

Following this sequence of events, the ObjectLookup and NetGUIDLookup on the server's PackageMapClient will end up in a bad state. In the ObjectLookup Map, the primary asset's package will be mapped ...

AssetRegistry: In a packaged game ScanPathsSynchronous with bForceRescan=true will permanently forget about assets inside IOStore containers

UE - Foundation - Data Pipeline - May 7, 2025

This came up from several discussions on UDN and internal discussion. The root cause is that the AssetRegistry currently cannot discover packages inside IOStore containers, it relies on the seriali ...

Fade local light shadow with r.Shadow.DoesFadeUseResolutionScale doesn't work with VSM

UE - Graphics Features - Shadows - May 2, 2025

When VSM is enabled, local light shadows don't fade even if r.Shadow.DoesFadeUseResolutionScale is true. Local shadows do fade based on resolution when using regular shadow maps (CSM). ...

ChaosWheeledVehicleMovementComponent is breaking the const CDO contract and changes to the instances are being applied to the CDO

UE - Simulation - Physics - Apr 28, 2025

As described by the licensee, the const CDO contract is being broken on ChaosWheeledVehicleMovementComponent. The issue the licensee is facing is that by spawning cars with different configurations, ...

Fatal error when creating listen server on an instance with a PendingNetGame

UE - Networking - Apr 28, 2025

This seems to occur because the PendingNetGame is not destroyed when the instance browses to the new level to start listening. In UEngine::LoadMap, UWorld::SetGameMode will create the game mode, pro ...

Fields with Maximum resolution are not affecting all leaves of a Geometry Collection

UE - Simulation - Physics - Destruction - Apr 25, 2025

Fields with Maximum resolution are not affecting all leaves of a Geometry Collection on 5.4 and onwards. When calling GetRelevantParticleHandles() a Maximum Resolution field does return all particl ...

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 ...

Niagara color picker user parameter preview no longer updates until confirmation

UE - Niagara - Apr 18, 2025

Starting with UE 5.4, the Color Picker Tool no longer updates preview values in real time for certain editor windows like Niagara when working with User Parameters. This behavior is a regression fr ...

WindDirectionalSourceComponent.h has a meta edit condition that, by referencing an undefined property (bSimulatePhysics), throws an error

UE - Framework - Apr 15, 2025

WindDirectionalSourceComponent.h has a meta edit condition that, by referencing an undefined class property (bSimulatePhysics), throws an error in the logs: LogEditCondition: Error: EditCondition pa ...