Unreal Engine Issues

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 ...

[Datasmith] Geometry in specific wire file is not tessellated

UDN - Crash reverting SkeletalMesh unsaved changes

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 ...

Nanite enabled Geometry Collection is not simulated by ChaosCache in package application

When using ChaosCacheManager to simulate destruction of a GeometryCollection, destruction is not simulated when Nanite is ON for the GeometryCollection. In the editor, destruction is simulated rega ...

Keep Playback Range In Section bounds can cause Actor Sequence range to be inclusive

FSequencer::UpdatePlaybackRange does not check the exclusivity of the new bounds when setting them, but UMovieScene::UpgradeTimeRanges does. ...

Replace Transform Track setting not used when importing FBX through scripting.

Importing the fbx uses the default settings, which aren't accessed through scripting, so they cannot be changed. To circumvent this  MovieSceneToolHelpers::ImportFBXIfReady caches the defaults, and ...

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 ...