Unreal Engine Issues

Lightmap UV generated on Windows and Mac is not deterministic

FDateRange cannot be declared as UPROPERTY

Unlike other range wrapper structs, such as FFloatRange, marking a FDateRange as a UPROPERTY results in the following error: error : Unable to find 'class', 'delegate', 'enum', or 'struct' with nam ...

Distributed HLOD builds always fail for projects not under the Engine Root

In BuildProject.txt, to make relative path to the project outside the engine root, all paths contains “..” after action command directory. D:/dev/UnrealEngine-5.5.0//HLODTemp/f09bf0f5/HLODBuilder0 ...

Reliable subobject creation bunch may overwrite previously received property on the actor

This seems to occur because of how reliability and the retransmission of dropped data is handled in the engine. If a reliable bunch is dropped, the entire bunch will be resent, but any unreliable bu ...

Iris - Fast Array ItemMap is empty in PostReplicatedAdd

With Iris enabled, the ItemMap is populated correctly only on the next frame, but it is empty during the callback. This differs from the behavior of the current system, where the ItemMap is populat ...

Level Instance desaturation effect does not respect occlusion when the selected object is occluded by a Nanite mesh

When selecting an asset in a level instance that is being edited via LevelInstance/Edit, the silhouette of the object is visible through occluding nanite meshes. This has the effect of disabling th ...

BakedSourceTexture missing from Sprite in packaged game

The UPaperSprite::BakedSourceTexture will be nullptr in a packaged game if the sprite is not referenced by the UGameInstance.  The attached sample project demonstrates this scenario. ...

Incorrect config property serialization for UStructs used as TMap keys or contained in a TSet with a single value. Diffs taken from default-value of each member type, instead of from default-value of the struct

Consider a UStruct with some basic type members, each one with a default value specified in the struct. Also consider a TSet or TMap with that struct as keys, used inside a UObject as a UProperty an ...

Play options menu vanishes sometimes

There seems to be something wrong with how we close menus and submenus as submenus are opened and closed based on mouse interaction. In particular, we seem to sometimes close the whole menu hierarch ...

Reduce the overhead of World Partition cells UObjects on GC

Users with large numbers of UObjects (500k+) that are using World Partition want to enable GC actor clustering to handle streaming levels but no performance gains are realized when enabling GC clust ...