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 ...

Nanite can assert in ValidateFixupChunk: 'Assertion failed: HierarchyNodeIndex < Resources.NumHierarchyNodes'

UE - Graphics Features - Nanite - Aug 29, 2024

Reported by a licensee. More discussion in the linked UDN case. "Sometimes the WorldPartitionBuilderCommandlet will fail after encountering this error:" Error: Assertion failed: HierarchyNodeIndex ...

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 ...

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. ...

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)); ...

FPropertySoftPath::Resolve doesn't resolve c-array elements properly

UE - Framework - Nov 20, 2023

a fix was proposed in the UDN but it needs to be tested and revised ...

Resolution retrieval issues caused by multi-monitor hot-swapping.

UE - Rendering Architecture - RHI - Feb 24, 2025

I looked into the underlying code, and it seems that this situation is not well handled. One possible solution is to trigger EnumAdapters() when the system fires the WM_DISPLAYCHANGE message. This ...

ENiagaraCoordinateSpace is not exposed to Python, meaning the FXConverterUtilitiesLibrary create_script_input_enum function does not work when setting that parameter.

UE - Niagara - Cascade - Apr 8, 2024

The user was having issues with setting the correct ENiagaraCoordinateSpace enum in their python script. This enum currently exists in the engine as both a user-defined enum (which is deprecated), a ...