Unable to create a 'World Soft Object Reference' Variable from the Variables Panel

UE - Framework - Blueprint Editor - Jun 21, 2018

Soft references to World objects (TSoftObjectPtr<UWorld>) cannot be directly created in blueprints. These types work fine in blueprints but cannot be directly created. The reason soft references are ...

USkeletalMeshComponent::HandleExistingParallelClothSimulation() calling WaitUntilTaskCompletes can trigger arbitrary task that modifies currently iterated UWorld::ComponentsThatNeedPreEndOfFrameSync

UE - Framework - Components - Feb 23, 2024

Context ActorComponents can schedule an end-of-frame update for themselves by calling UWorld::MarkActorComponentForNeededEndOfFrameUpdate. The UWorld will iterate all those actor components once pe ...

Unexpected behavior when Actor Parenting in the World Outliner of a WP map

UE - World Creation - Worldbuilding Tools - World Partition - Nov 23, 2021

Licensee reports the following in the UDN: There seems to be some other erratic behavior when using parenting in world outliner (i.e. drag and drop one actor on another one in world outliner).Since ...

ULevelSequence trying to duplicate a REINST_ class when creating new custom binding in ConvertOldSpawnables()

UE - Framework - Blueprint Compiler - Jul 23, 2025

The assert that we're hitting is:Cannot replace existing object of a different class.  New Object: /Engine/Transient.REINST_BPC_NPC_VFX_C_230 /Game/Maps/[REDACTED]/Levels/[REDACTED]/LevelSequence/ ...

Unloading a World Partition region during nested Level Instance inline editing prevents exiting editing mode

UE - World Creation - Worldbuilding Tools - Level Instances - Jul 28, 2025

In the case of a single-layer Level Instance, actors are still referenced even when the region is unloaded. However, in the case of nested Level Instances, the level being edited is discarded when t ...

Fatal Error when setting S RGB to true on a Texture 2D from a Render Target Create Static Texture Editor Only node

UE - Texture - Jun 6, 2022

This is a regression. Tested in //UE4/Release-4.27 CL#18319896 Fatal Error when setting S RGB to true on a Texture 2D from a Render Target Create Static Texture Editor Only node. ...

Interaction between sublevels and LevelSequences can break actors attachments hierarchy of the sublevel.

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

Having a LevelSequence opened and unhiding a sublevel can break the attachment hierarchy of the actors that are inside the sublevel. This also affects to the sublevel asset itself. ...

Copying a Folder that contains the space character from the Outliner does not enclose the Folder name on Double Quotes. Because of that, later Pasting will only handle the first word of the Folder name.

UE - World Creation - Worldbuilding Tools - Jun 10, 2025

Copying a Folder that contains the space character from the Outliner does not enclose the Folder name on Double Quotes. Because of that, later Pasting will only handle the first word of the Folder n ...

Ensure/failure when changing the class of a scene component that has bVisualizeComponent enabled

UE - Framework - Blueprint Editor - Oct 20, 2023

Failure occurs at compile time during GC when the replacement component that we create is being destroyed. This component includes the BillboardComponent instance that's attached to the scene compon ...

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)); ...