In Standalone mode, when reading world partition actor descriptors for BP actors, "bIsSpatiallyLoaded" receives its value from the native base class instead of the BP class, so BP actors are loaded/unloaded based on the wrong condition.

UE - World Creation - Worldbuilding Tools - World Partition - Oct 15, 2024

Consider an actor defined in C++ with "bIsSpatiallyLoaded" set to true (the default), and a derived blueprint that overrides "bIsSpatiallyLoaded" to false. Now consider an actor instance of that blu ...

CitySample - Level MassCrowd - interactions with SmartObjects/ContextualAnimScene is broken in 5.5

UE - AI - Apr 9, 2025

The 5.5 version of the CitySample project, particularly the MassCrowd scene, was not properly maintained. The previously working functionality of NPCs being able to sit on a bench is now broken. CAS ...

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 ...

CPF_TextExportTransient and RF_TextExportTransient inconsistent behavior

UE - Framework - Blueprint - May 23, 2024

The TextExportTransient can be specified as a property flag and object flag. Behavior is inconsistent: there are many ways in which an object marked TextExportTransient can still be part of the text ...

Deleting transient actor marks level dirty

UE - World Creation - Worldbuilding Tools - Feb 6, 2025

The licensee has noticed that the deletion of a transient actor still marks the scene as dirty and asks it to be saved. Checking the source it was noted that the transient flag is not verified on de ...

"Build All Levels" does not re-AddNavigationSystemToWorld

UE - AI - Navigation - Feb 28, 2024

The Build All Levels editor action cleans up the world's NavDataSet (UNavigationSystemV1::NavDataSet) as pre-rebuild world cleanup by calling: SetNavigationSystem(nullptr); inside UWorld::Cleanu ...

Focus mode in the Editor does not handle Actors without PrimitiveComponent correctly, treating them as if they were at the origin (0,0,0), skewing the camera placement.

UE - World Creation - Worldbuilding Tools - Nov 18, 2024

Focus mode in the Editor does not handle Actors without PrimitiveComponent correctly, treating them as if they were at the origin (0,0,0), skewing the camera placement. Some Actors like the WorldDat ...

Editor crash while saving asset during cook operation

UE - Foundation - Data Pipeline - Cooker - Apr 2, 2025

It is possible to experience an editor crash in 5.5.4 when the cook process generates a warning that references an asset while the editor is saving. It seems that during a save operation, the code t ...

Spawnable Level Instance via Sequencer in WP map

UE - World Creation - Worldbuilding Tools - Level Instances - Aug 21, 2023

ULevelInstanceSubsystem::OnActorDeleted: check(!IsEditingLevelInstanceDirty(LevelInstance) && !HasDirtyChildrenLevelInstances(LevelInstance)); ...

Deprecated blueprint variable fixups may fail depending on loading order

UE - Framework - Blueprint - Mar 7, 2024

There is currently no simple way to do a deprecated variable fixup on native variables that are set by a blueprint class. For a simple variable rename, CoreRedirects can be used and will work proper ...