Unreal Engine Issues

Cumulative Patching does not work with Pak signing

Cumulative patching is implemented by copying the generated pak files during staging of the base and each patch to the Releases directory. When creating a patch, all of the pak files from the releas ...

Copied Actors in World Partition Levels Maintain References to Actors They Are Copied From

When an Actor is duplicated in the editor inside a world partition level it maintains references to the Actor it is a copy of. This can cascade, i.e. Actor C, which is a copy of Actor B which is a c ...

MustBeMappedGUID errors after several seamless travels

This seems to be the same issue as was reported in [Link Removed], as enabling net.ResetAckStatePostSeamlessTravel resolves the issue. However, it was recently reported that disabling net.FilterGuid ...

Blueprint "Diff Against Depot": Restoring an instanced object results in reference to the object in the temporary diff asset

When diffing a blueprint against depot via the Content Browser context menu action "Revision Control > Diff Against Depot", restoring an instanced object property from the depot version results in t ...

StreamableManager completion callback can happen after being canceled in same frame

FStreamableHandle (used as part of the FStreamableManager system) has a CancelHandle function that stops it from calling any completion callbacks related to that handle (it could cancel the load req ...

MoviePlayer loading screen with FLoadingScreenAttributes::bAllowEngineTick results in high DeltaSeconds tick post-playback

IGameMoviePlayer playback of a movie during loading screen lets you set bAllowEngineTick  = true as a parameter. This will make FDefaultGameMoviePlayer manually tick the engine: if (GEngine && bAll ...

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

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 ...

Rect + Spot Light Anomalies when Baked with GPU Lightmass

Missing Dynamic Shadows when forcing volumetric lightmap only for static meshes

Components added in Blueprint that want initialisation are not maintained by RerunConstructionScripts

When a native component that wants initialisation is added to a Blueprint actor in the Blueprint editor, the initialisation state of this component will not be correctly preserved by RerunConstructi ...