Directional light triggers 'too many overlapping lights' error in forward shading

UE - Graphics Features - Sep 24, 2019

The underlying reason seems to be that the stationary lights require SM channels for casting shadows  from movable objects and they are assigned channels 0,1,2 by lightmass (or somewhere along the w ...

Niagara module inputs don't handle bitfield enums correctly

UE - Niagara - Feb 17, 2025

As one clicks on the enum fields trying to form an input, the log is written with a variation of the following: [2025.02.14-17.42.38:940][521]LogNiagaraEditor: Error: Error getting default value fo ...

Merge Actors Tool Simplifies Nanite Meshes

UE - World Creation - Worldbuilding Tools - Merge Actor - May 19, 2023

Tried every combination of LOD Selection Type, Nanite enanbled/disabled, the only way it would seem to get the full number of triangles from the source mesh into the merged mesh is to disable Nanite ...

Optimize Data Layer runtime state replication

UE - World Creation - Worldbuilding Tools - Data Layers - Dec 7, 2023

[Link Removed]This issue occurs only when I have a lot of RDLs (I tested 2500 and 1600). I tested with 6 RDLs and had no issuesI also noticed in the server log an error when a lot of RDLs are presen ...

"Current state is a conduit and will reset to ref pose" warning when using a conduit to select an entry state

UE - Anim - Gameplay - Dec 12, 2022

AnimBlueprintLog: Error: Current state is a conduit and will reset to ref pose. This can happen if a conduit is an entry state and there isn't at least one valid transition to take. State Machine(Te ...

Cable Actor becoming stiff when bound to two dynamic objects

UE - Simulation - Physics - Jun 1, 2023

the cable actor does not dynamically deform when the cable actor's parent mesh moves. Instead, the cable actor becomes rigid between the meshes it's bound between. This bug does not occur in the fo ...

Call-In-Editor functions in an EditorUtilityActor are not called in editor

UE - Framework - Blueprint - Mar 22, 2024

In 5.1 through 5.3, Call-In-Editor functions within EditorUtilityActor Blueprints created via Create Advanced Assets/Editor Utilities/Editor Utility Blueprint are not callable in editor. Prior to 5 ...

Nanite Tessellation Artifacts With Landscapes

UE - Graphics Features - Nanite - Dec 4, 2024

There seems to be an issue with how Nanite tessellation and Landscape interact with two sided landscapes. When the camera's near clipping plane is past the landscape's surface the displacement of th ...

Python crash the engine at exit.

UE - Editor - Workflow Systems - Oct 25, 2022

A UDN reported various crashes at exit in the embedded Python library. I was able to repro the issue in Release-5.1 and trace it back at the point where python runs its garbage collection in Py_Fina ...

SubCategory of UFUNCTION does NOT work properly if using CallInEditor

UE - Gameplay - Blueprint Editor - Sep 20, 2022

If you use both Category hierarchy and CallInEditor in UFUNCTION, it will result in an unintended sequence as shown below. [Image Removed] And, the following code can solve this issue void FDetai ...