Renaming a BP interface function/event breaks all existing uses of that function/event

UE - Gameplay - May 24, 2018

If you rename a blueprint interface function or event that is used somewhere in a blueprint, it will break the usage of that function/event. If it was a function, it will actually delete all the BP ...

Creating SplineMeshComponents along Spline causes crash

Tools - Aug 22, 2018

Attempting to procedurally create SplineMeshComponents along the spline of a SplineComponent via a derived SplineComponent class's constructor causes the project to crash. It runs into an ensure mes ...

Rect Light Source Creates Black Artifacts When Overlapping a Mesh While Light Shaft Bloom Is Enabled

UE - Graphics Features - Nov 9, 2018

A black line will appear If a Rect Light is overlapping a mesh while a Directional Light has light shaft bloom enabled. This line will originate from where the edge of the source is overlapping the ...

Moving .uassets that were imported from a source file with Source Control active moves the source file without marking for add

Tools - Feb 26, 2019

A licensee has reported an issue with Perforce source control integration. The issue is related to the source file for an asset that was imported into the editor. If this source file is also checked ...

r.AllowOcclussionQueries causing "huge RenderQuery Result" wait time in VR

UE - Graphics Features - Dec 3, 2019

Running r.AllowOcclusionQueries 0 command seems to set bWait = true, causing large wait times Tested: 4.22.3 CL#7053642 ,   4.24P4 CL#10387632 , 4.25 CL#10479005 Link to the users video, which ...

Pawn's role is incorrect in BeginPlay on client if a multicast RPC is called in BeginPlay on server

UE - Networking - Jun 6, 2022

It seems as though calling a multicast RPC during BeginPlay on the server will cause the new actor to finish spawning on the client before applying any initial replicated data, such as the actor's R ...

Merging Splines causes Engine to Crash in 5.1

UE - World Creation - Worldbuilding Tools - Merge Actor - Dec 15, 2022

Attempting to merge two spline actors causes the Engine to crash. This issue occurs with the Steps to Reproduce regardless if there are more branches added to the tree branch spline/enabled, and reg ...

LOD dithered fade-out transition does not work since UE5.4

UE - Rendering - Architecture - Aug 7, 2024

When DitheredLODTransition is enabled for HierarchicalInstancedStaticMesh, in the previous version (5.1.1), dithering was applied during fade-in/fade-out, but in 5.4.3, dithering is not applied duri ...

Modifying Notify Properties no longer updates the NotifyName in Blueprints with custom GetNotifyName function.

UE - Anim - Gameplay - Feb 13, 2025

If after placing a notify on an anim sequence timeline you modify a property that is used in the GetNotifyName function of a blueprint notify in engine version previous to 5.5 (5.4.3 for example) th ...

Materials for certain groups appear black in Path tracer when "Keep hierarchy" is used to import .skp files.

TM - Interoperability - Mar 3, 2025

Reported by a client in SF [Link Removed] When importing SKP files using the Keep Hierarchy collapse mode, some imported objects in Groups inside SketchUp will appear black in Path Tracer. Appears ...